The Comprehensive Guide to Portal 2

A complete guide to Portal 2, covering gameplay basics, background, all objects and game mechanics, a full walkthrough of both the single and multi-player campaigns, secrets, and help for getting all achievements.

About This Guide

THIS GUIDE (INCLUDING THE TABLE OF CONTENTS) CONTAINS SPOILERS!

So I was recently going through some old computer files and ran across a complete guide to Portal 2 that I wrote a long time ago and never published. So I decided to clean it up and put it out on Steam.

While this guide is comprehensive in terms of the content of the game, attempting to document all possible solutions to the in-game puzzles would be impractical, not to mention boring. Instead, in this guide, a solution to a puzzle will be presented because it is the easiest, most straightforward, or "intended" way to solve it. Other ways of solving puzzles certainly exist, including some very cool "ninja" solutions, but they will not be documented here. If you're really a ninja player, you don't need this guide anyway.

Also note that this is guide is complete as of the date of writing. It is possible (though unlikely) that the game may be updated by Valve; if so, such an update may alter gameplay in ways not covered by this guide.

In the section headers, the course names given in double quotes are the names given in the challenge mode, which was added in the downloadable content released on October 4, 2011.

GAMEPLAY OVERVIEW

The following sections describe all of the elements and mechanics of Portal 2.

Gameplay Modes

Single Player Campaign

The single player campaign is a continuation of the storyline from the first Portal game, playing as Chell. After destroying GLaDOS, she ends up sprawled on the ground in the Aperture Science parking lot, where the Party Escort Bot finds her and drags her back into the facility, placing her in an Extended Relaxation Chamber. However, GLaDOS's destruction has caused the facility's stasis systems to go offline. Without life support, Chell would surely die.

However, these events were witnessed by Douglas Rattmann, a former Aperture Science employee hiding from GLaDOS and eking out an existence behind the walls. He manages to activate the stasis system for Chell's chamber, ensuring Chell's survival. Portal 2 starts many years later as Chell is woken by Wheatley, a personality core which proposes they work together to escape the facility.

Co-op Campaign

The co-op campaign is a separate storyline, where players take the roles of two robots named ATLAS and P-Body. As revealed in the final chapter of Portal 2, they were created by GLaDOS near the end of the original Portal storyline to replace human testing. ATLAS and P-Body work together to complete five test courses; the "Peer Review" Portal 2 DLC added a sixth one called "Art Therapy."

Challenge Mode

This gameplay mode was added as part of the first Portal 2 DLC. It adds a "finish line" to various levels from the single-player and co-op campaigns. Players attempt to reach the finish line in the fastest time or placing the fewest portals.

Perpetual Testing Initiative (PeTI)

The second Portal 2 DLC added a simplified chamber editor, allowing players to create and share their own test chambers without having to learn the complex Hammer editor. Levels created by others can be easily downloaded directly from the game client and played immediately. The storyline is this: In an alternate universe, Cave Johnson has come up with a plan to save Aperture Science from bankruptcy: deliver the plans for test chambers to other alternate universes, let their versions of Aperture Science build them, then steal them back. In these chambers, the player takes the role of "Bendy," a stick figure as seen in the promotional videos released by Valve. The third Portal 2 DLC added co-op capability to PeTI, allowing players to design and play custom co-op chambers.

Default Controls

Action	PC/Mac	PS3	XBox 360
Look	mouse move	right stick	right stick
Move	WASD keys	left stick	left stick
Jump	space bar	X	A
Crouch	Ctrl	circle	B
Fire 1	LMB	L1	L
Fire 2	RMB	R1	R
Use	E	square	X
Zoom	mouse wheel	R2	RB
Toggle zoom	MMB	n/a	n/a
Partner view	Tab	triangle	Y
Gesture menu	Q	D-pad down	D-pad up
Ping tool	F (hold)	L2	D-pad left
Quick ping	F	D-pad right	LB

Characters

Below is a list of characters you will encounter, in the order in which they (or their influence) can be encountered earliest in the game.

Chell

The protagonist. She defeated GLaDOS in Portal 1 and escaped the facility, only to be dragged back in by a robot and put into suspended animation. She is woken many years later by Wheatley, who wants her help in restoring the facility. After defeating GLaDOS for the second time, she is forced to team up with her to defeat a power-mad Wheatley. She is subsequently released to the surface by GLaDOS for being too hard to kill.

Announcer

An artificial personality in charge of the Aperture facility during GLaDOS's deactivation, and who guides Chell through the early chambers after she is reawakened. He is rarely heard from after GLaDOS's reactivation.

Wheatley

A hilarious but rather dim-witted personality sphere with a blue eye and a British accent, who wakes Chell to get her help. Eventually, you succeed in putting him in charge of the facility, but he goes mad with power and becomes the main antagonist. He is eventually defeated by being sucked out into space through a portal.

Douglas Rattmann

A former Aperture Science employee who survived GLaDOS's takeover. He is never encountered in the game, but you do run across his dens in areas behind the walls, where he hid out from GLaDOS. In the comic Portal 2: Lab Rat, he is shot by turrets while activating Chell's stasis chamber. He likely died from his wounds. Even if he survived, he's probably long dead when Chell awakes from stasis in Portal 2 many years later.

Oracle Turret

A friendly turret that you'll encounter twice in the game. It has a few rather cryptic things to say which foreshadow later events.

GLaDOS

Your nemesis from Portal 1 is back, and she's pretty bitter. You know, because you killed her and all. After you accidentally reactivate her, she puts Chell through more test chambers until you and Wheatley (mostly you) defeat her. When Wheatley takes over the facility and goes crazy, he puts GLaDOS's personality core into a potato battery. (Her potato form is referred to as PotatOS.) She is then forced to team up with Chell to defeat Wheatley and is reinstated as the personality core in charge of Aperture.

The Bird

Wheatley is attacked by a bird during Chell's run through the reactivated GLaDOS's test chambers. When Chell and PotatOS fall into Old Aperture, this bird takes PotatOS to her nest and starts eating her before Chell chases her away. She is later the "main antagonist" of the Art Therapy course of the Peer Review DLC, where she has built a new nest in a prototype central core chassis. The Bird is chased away, leaving behind its eggs; GLaDOS adopts the chicks when they hatch, intent on turning them into "killing machines."

Jerry

A nanobot management core working in the facility. Wheatley briefly works under him rebuilding the facility while trying to hatch a plan for him and Chell to escape. Chell encounters him once between test chambers in chapter 4. As a nanobot, Chell cannot see him, but his very rapid voice is heard.

Cave Johnson

The founder of Aperture Science. You never encounter him in person, but you do hear his voice in prerecorded messages and see his picture up in various locations. He serves to introduce the puzzle elements you encounter in the middle third of the game, and it is through him that you learn of GLaDOS's backstory.

Caroline

Cave Johnson's assistant, whom you also meet through the prerecorded messages. You learn during your time at Old Aperture that her personality was inserted into a computer. The process made her unstable and turned her into GLaDOS.

ATLAS and P-Body

Two robots created by GLaDOS near the end of the first game (though not seen at that time), with the objective of eliminating the need for troublesome humans for testing. They are the player characters in the co-op campaign. You see both of them at the end of the single-player campaign, but P-Body makes a brief appearance as an Easter egg in one of the test chambers.

Space Sphere

The first of three corrupted cores you encounter at the final boss fight. The Space Sphere is completely obsessed with going to space. At the end his wish is fulfilled, as he gets sucked out into space along with Wheatley.

Rick the Adventure Sphere

The second corrupted core encountered during the fight with Wheatley, Rick acts like a tough guy, boasting of his brave adventures, despite having no arms or legs. He even brags about having black belts in many disciplines, despite not having a waist. He is always excited to face danger and is both flirtatious and chauvinistic toward Chell. When Chell opens a portal to the moon, Rick is immediately sucked out into space and is not heard from again.

Fact Sphere

The final corrupted core encountered during the boss fight, the Fact Sphere continuously spouts "facts," most of which are false. Unlike the other cores, the Fact Sphere avoids being sucked out into space at the end.

Bendy

The main stick figure seen in Portal 2 promotional videos, Bendy is the player character in community test chambers.

Greg

In the alternate universe that is running the Perpetual Testing Initiative (PeTI), Greg is Cave Johnson's assistant rather than Caroline. His voice is heard in audio recordings, but it is muffled like that of Charlie Brown's teacher.

Portals

Portals are the primary gameplay mechanic of the game. When two portals are established, they will be linked, and any object (including yourself) which passes into one immediately exits through the other.

In single-player games, only two portals may exist at once. One portal is blue and the other is orange. (The colors only help you distinguish which portal is which; they are functionally identical.) In the co-op campaign, each player controls their own pair of portals. ATLAS's portals are cyan and purple, while P-Body's are yellow and red.

If only one portal of a pair exists, it is unlinked and objects will not be able to pass through it. It will link once the other portal is placed; you can tell that it is linked because you will be able to see through it. If a portal is created when another of the same color already exists, the old portal of that color will collapse. You can always tell the color of the most recent portal you have shot by looking at the indicator light on top of the portal gun.

Portals may only exist on surfaces which accept them; these are typically light-colored and appear to be made of a substance like concrete. Darker, metallic-looking surfaces don't accept portals. Neither does glass or grates. Some surfaces which normally don't accept portals can be made to accept them by painting them with conversion gel.

You can bring objects through portals; and lasers, hard light surfaces, gels and excursion funnels can travel through them as well. Turrets can see and shoot at you through portals in the single-player and co-op campaigns, but cannot in chambers designed in the built-in test chamber editor. If a portal collapses while something is in it, that object will be pushed out one way or the other; it won't be destroyed.

Testing Elements (single-player)

Aerial Faith Plate

When you touch a faith plate, it will catapult you through the air. Most will throw you in an arc to another location, but some will shoot you straight up. You can also place objects on faith plates to have them catapulted.

Cube (a.k.a. Weighted Storage Cube)

The most common use for a cube is placing it on a button. However, cubes have other uses. These include but are not limited to blocking laser beams, serving as riot shields to protect you from turret fire, or functioning as projectiles for knocking turrets over. Cubes have undergone a slight change since Portal 1, now designed to light up when placed on a button or in a receptacle. The Companion Cube also returns, and you can hear a faint tune when you are standing near one.

Button (a.k.a. Heavy Duty Super-Colliding Super Button)

The large red buttons you'll find in the facility will activate when pressed and deactivate when released. Buttons are typically located on the floor, where you can stand or put a cube on it to activate it. Sometimes, they're found on the wall or ceiling, in which case you'll need to hold an object on it with an excursion funnel. Most buttons are round, but the ones found in the old Aperture Science facilities are square.

Dispenser

A circular port (or sometimes square in Old Aperture) in the ceiling which drops items such as cubes, gel or water; either automatically or when activated with a pedestal button. If you activate a cube dispenser when a cube it previously dropped is already in play, the old cube will be fizzled. In many cases, the reverse is also true: if a cube gets fizzed, the dispenser that originally dropped it will frequently drop another one automatically. In co-op, you and your partner spawn via dispensers, as well.

Excursion Funnel

These tunnels of blue light work like tractor beams. Anything caught within one is moved gradually along its length. You can travel in them, as can other objects and gels. If you are in one and want to get out, simply move out of it. They do not protect you from turret fire. Sometimes pressing a button or activating a device will will cause them to turn orange and reverse direction. Excursion funnels are projected by a surface-mounted emitter device.

Exit

Your goal in most chambers is to reach the exit. In most chambers, they're round and have a blue stick figure on it. In Old Aperture, they're plain gray rectangular doors.

Fizzler (a.k.a. Material Emancipation Grill)

A blue force field. All objects which touch it will be disintegrated except for you, the portal gun, Wheatley, PotatOS, gel and turret bullets. Fizzlers also block portal shots, and cause the portal gun to reset when it passes through them, closing any open portals. Most frequently, they'll be found across elevator doors and certain other doorways to separate puzzles (by wiping out your portals), though sometimes they're part of a puzzle, too.

Frankenturret

Frankenturrets are the result of an ill-advised experiment which combined a cube with two turrets. You'll find them starting at Chapter 8. They're harmless and can be used just like regular cubes, but have a tendency to walk away. To prevent this, drop one while you have a little forward momentum. This tips it onto its back so that its legs can't touch the floor.

Gel

A substance which alters the properties of surfaces you paint with it. There are three types of gel: repulsion gel, propulsion gel, and conversion gel.

Goo

Goo looks like really nasty water. Any objects that fall into it (including yourself) are destroyed. If you lose an object which is vital to solving a test chamber in this way, don't worry; you will always be able to get another (unless you're in a rather badly-designed community test chamber).

Hard Light Surface

A hard light surface is a kind of force field that is projected from a surface-mounted emitter in a narrow strip. They can act as bridges and walls that you can move with portals, allowing you to reach areas that were otherwise inaccessible or block projectiles. Turrets can't see you at all through hard light surfaces, so they make excellent shields. Portal shots and other hard light bridges pass right through them, but they block lasers and gel will collect on them.

Grate

While grates block you and most objects from passing, you can shoot portals and lasers through them, and turrets can shoot bullets at you through them.

Laser Beam (a.k.a. Thermal Discouragement Beam)

Laser can be redirected with portals or pivot cubes. While a laser will hurt you, it's difficult to be killed by one; you'll simply be pushed away. They can, however, easily destroy turrets. Lasers are generated at a surface-mounted emitter. Often, you will be required to redirect them to strike a receiver to activate a device.

Laser Field

An array of red laser beams, acting as sort of counterpart to the fizzler: instead of destroying objects but allowing you to pass, the laser field allows objects to come through unharmed but will kill you. Portal shots will pass through a laser field. Despite looking quite similar to regular lasers, the beams in the field cannot be redirected with a pivot cube. Like many other test objects, a laser field can be activated and deactivated. For some reason, the laser field only appears once in the single-player campaign and not at all in co-op.

Laser Relay

This floor-mounted device is like a laser receiver, except that it is designed to have a laser shot through it and out the other side. This means that you can activate more than one with a single laser beam.

Movable Panel

A panel (portal-accepting or otherwise) which can be moved with actuating arms. Some can be activated at will, but most are just eye-candy, showing the process of the facility being rebuilt.

Pedestal Button

These are like the large red buttons, but smaller and situated on a small pedestal. You activate them by pressing the USE button. These cannot be held down like regular buttons, but simply trigger a device each time you press it. For example, dispensers are usually accompanied by a pedestal button, which you can press to fizzle the last item it dropped (if it hasn't already been destroyed) and dispense a new one.

Some pedestal buttons trigger a timer. When you press one and hear a ticking sound, you have a limited amount of time before whatever the button activated turns off again. The activated device will have a small display next to it which will show how fast the time is running out.

Pivot Cube

A cube with lenses on the sides. It functions exactly like a regular cube, with the added feature that it can be placed in a laser beam to redirect it. When held, a pivot cube will always redirect any beam it intercepts away from you in the direction you are facing.

Portal Generator

A bracket on a wall which will produce a portal automatically. They don't show up after you acquire the two-portal gun, since you don't need them anymore after that.

Turret

Turrets look like white, egg-shaped things on three legs. They have a red eye from which a red aiming beam projects. When you come into view, they will lock onto you with this beam, then fill you with bullets.

Unstationary Scaffold

A platform that moves horizontally. Unlike their Portal 1 counterparts, they move on a wall-mounted track rather than a beam of light, and unlike victory lifts, they never move automatically upon standing on them.

Victory Lift

A platform on a piston which can be raised and lowered. Some of them activate as soon as you stand on them, but most are activated by other devices.

Water Flow

Flowing water cleans gel from surfaces and objects. You'll only find it in a small number of places, flowing from dispensers. Like gel, water flows can be redirected with portals.

Testing Elements (co-op)

The following testing elements are found only in the co-op campaign:

Ball (a.k.a. Edgeless Safety Cube)

These serve the same function as normal cubes. However, being round, they tend not to stay where you put them.

Dual Door

These doors are found throughout the co-op campaign. GLaDOS watches you through a camera mounted on the wall next to it. When you enter the range of the camera, a light appears on it, and the indicator for your color above the door changes. When both robots are in range, the door will open.

Receptacle

This device works like button, but it can only be activated by placing the appropriate object on it. There are two variants: the cube receptacle (which accepts only cubes, including pivot or companion cubes) and the ball receptacle (which accepts only balls). The flat button surface is replaced with a "container" that will be square or round, depending on which object it accepts.

Other Objects

This list describes other objects you may encounter besides formal testing elements:

Ant Line

A trail of blue circles that connects an object to the device which activates it. They light up orange when you activate it. Sometimes you'll see a symbol next to each device instead.

Bomb

Bombs are transported through some pneumatic tubes. Obviously, they can harm or kill you if they explode near you, but you can use them to break other pneumatic tubes carrying gel. They also come into play in the final boss fight.

Camera

Used by GLaDOS to keep an eye on you. The cameras start out powered down, but after GLaDOS is reactivated, they follow your movements as in the first game. Also like the first game, they can be detached from the wall with portals, but this time there's no achievement to be earned from doing so.

Chamber Selector

In The Hub, each course door has a short corridor behind it which leads to the disassembly machines. In this corridor is the chamber selector, a device which displays the status of each chamber (locked, unlocked, completed) for each player. A black selection cursor shows which chamber is your current destination. You can change the selection by using the left and right buttons on the device.

Chamber Sign

These backlit signs have returned from the first game. They display the number assigned to this chamber in large digits. They also show a progress indicator showing how far through this particular testing gauntlet you've proceeded, and a number of icons indicating the challenges, hazards or required skills for the chamber.

Conveyor Belt

You'll encounter a few of these in the turret manufacturing plant, and one in the final chapter. They behave as you would expect.

Course Sign

In The Hub, the door leading to each course has a sign above it which identifies the course and shows which chambers in that course have been completed by each player.

Crusher (a.k.a. Mashy Spike Plate)

Don't stand around in front of one of these or you can get killed. In co-op, some of these can be activated like other devices.

Defective Turret

Also called "crap turrets" by Wheatley, defective turrets typically lack the distinctive white shell that regular turrets have. They are both harmless and hilarious.

Disassembly Machine

The co-op equivalent of the end-of-level elevator. There are two (one for each robot) at the end of the calibration course, in the entrance to each course in The Hub, and at the end of all test chambers except the last in the first four courses. Each robot must step into their corresponding disassembly machine to proceed. In the last course, they're replaced with plain chutes which drop you unceremoniously down a tube.

Disc Drive and Disc

A disc drive is found at the end of each of the first four co-op courses. You have to find a disc, bring it back to the drive and insert it.

Elevator

Elevators transport you between most test chambers.

Finish Line

The finish line appears only in challenge mode. It looks like a floating hologram of two crossed checkered flags. The objective in challenge mode is to touch the finish line as quickly as possible, or using as few portals as possible. Upon touching the finish line, your results will be displayed and compared with those of your friends and the global Portal 2 community, with an appropriately pithy comment from GLaDOS.

Lever

These knife switch-style levers are found in the old Aperture Science areas. They turn on lights and activate machinery.

Monitor

Starting in Chapter 8, you'll see a number of large display monitors showing Wheatley on them. There are 22 in total. You encounter 15 in chapter 8, 11 of which can be broken. Chapter 9 contains seven monitors, and only one can be broken. Breaking all the breakable monitors in chapter 8 (across any number of runs) will earn an achievement. There are three methods for breaking one:

• Lob an object (such as a frankenturret or yourself) at it with sufficient force
  
• Shoot a laser at it
  
• Move a turret so that it will shoot it

Wheatley will make unique comments each time you break a monitor. To hear all of them, you have to break all the monitors in a single run.

Neurotoxin

A greenish poisonous gas. Anytime there's neurotoxin around, a wall-mounted display will show exactly how much time you have to escape before you're killed. The only place you're guaranteed to encounter it is during the final boss battle, but it can show up in a couple of other places.

Rattmann Den

These are places where Douglas Rattmann had stayed while hiding from GLaDOS around the time of the first game. They're mostly just for atmosphere and backstory, but one of them is significant for an achievement, another contains an unusual commentary node, and several foreshadow events at the end of the game.

Small Button

Regular old buttons. They're red, but smaller than the ones for boxes and they're not situated on pedestals. A few behave like pedestal buttons, in that they control something you can activate as many times as you like. Others can only be activated once, but once is all you'll need.

Socket

This is a device that you can use to connect Aperture Science personality constructs (such as Wheatley) to the Aperture Science network. Just push it into the socket to connect it (although sometimes you'll have to press the USE button).

Spinning Blades (a.k.a. Spinny Blade Wall)

Pretty obvious: Don't touch them or you die.

Stalemate Button

This important device resembles a standard pedestal button, but doesn't activate a device in the room. Instead, it... well, it'll make sense when you get there.

Vitrified Door

There are six of these sealed metal doors in the game, all in the old Aperture Science areas. You can't open them, but each has a little button panel to the right, which plays a recording when activated. Activating all six earns an achievement, but it isn't required to complete the game.

Dealing with Turrets

Turrets are one of the few things that can outright kill you in Portal 2. You will often see its harmless targeting laser before you see the turret itself. When you enter their field of vision (90 degrees), they will lock onto you with their laser, then after a short delay, open fire. They can shoot through grates and fizzlers. In the single-player and co-op campaigns, they can also shoot through portals, but they cannot in chambers created using the built-in test chamber designer. Interestingly, they will also shoot at the large monitors you find in the test chambers in Chapter 8 of the single-player campaign.

There are several ways to avoid getting shot:

• Don't enter their field of vision
  
• Hide behind a wall, cube, pane of glass or hard light surface
  
• Hold a cube and use it as a riot shield

There are also many ways to permanently defeat a turret:

• Approach it (preferably from outside its field of vision), pick it up, and toss it on the ground
  
• Drop a portal under one to throw it somewhere else
  
• Drop it into goo or into a fizzler
  
• Pick up an object, such as a cube, and club the turret with it
  
• Use portals to throw an object at it
  
• Hit it with a laser beam
  
• Pick it up with an excursion funnel
  
• Hit it with repulsion gel

Unlike the turrets in Portal 1, picking up a discarded turret and putting it back on its legs will not reactivate it. Chell won't die from one bullet, but two or three seconds of sustained fire will kill her. If she's not killed, Chell will return to full health after a few moments; how she is able to do this is never explained.

Gels and Water

During the course of the game you will encounter four liquids dripping or pouring out of dispensers or pipeline breaks: water and three different types of gel. (Sometimes you will have to activate a dispenser first to get the liquid to come out.) You can use portals to redirect liquids, and transport them with excursion funnels. Gels will paint most surfaces and objects they come into contact with (including hard light). Water will clean gel off of surfaces. A portal-receptive panel that is painted with gel will still accept portals. When a gel-coated surface is painted with a different type of gel, the effects of the previous gel are nullified.

The three types of gel are (in the order in which they are encountered in the single-player campaign):

• Repulsion gel: Surfaces painted with this blue substance will cause objects which strike them (including you) to bounce. Objects that get painted with it will bounce around like super balls. If you wish to land on a repulsion gel-painted surface without bouncing, hold down the crouch button when you come into contact with it.
  
• Propulsion gel: When a floor or ramp is covered with this orange gel, you can run over it very quickly. An object painted with it becomes slippery, and will slide down an incline where friction would normally keep it in place.
  
• Conversion gel: A surface which does not normally accept portals can be made to accept them by coating it in this white gel. Conversion gel has no effect on objects.

What Goes Through What?

Portal 2 is all about manipulating various materials, so it's important to know how they interact:

	Portal	Glass	Fizzler	Grate	Hard light	Laser field
Player	Passes	Blocked	Passes	Blocked	Blocked	Killed
Portal shot	Blocked	Blocked	Blocked	Passes	Passes	Passes
Laser beam	Passes	Passes	Passes	Passes	Passes	Passes
Turret vision	Passes(1)	Passes(2)	Passes	Passes	Blocked	Passes
Turret fire	Passes(1)	Blocked	Passes	Passes	Blocked	Passes
Hard light	Passes	Blocked	Passes	Blocked	Passes	Passes
Gel/Water	Passes	Paints	Passes	Blocked	Paints	Passes
Funnel	Passes	Blocked	Passes	Blocked	Blocked	Passes
Other object	Passes	Blocked	Fizzled	Blocked	Blocked	Passes

1. In the single-player and co-op campaigns, turrets can see and fire at you through portals. In maps created using the in-game editor, they cannot. Valve explains that playtesters found that allowing turrets to shoot through portals meant that a player might place a portal and suddenly get shot without warning. The Valve-created maps are carefully designed to avoid this being a problem too much, but there's no such guarantee for community-created maps, so Valve chose to disable turret fire via portals for maps created in the in-game editor.

2. Turrets can always see you through glass, and will usually hold their fire until you come out into the open. In rare cases, however, they will open fire even while you are still behind the glass. Course 01 chamber 07 of the co-op campaign is a good example. What causes the difference in behavior is unknown.

Console Commands

On desktop versions of Portal 2, you can access the developer console by enabling it in the options menu, then pressing the backtick key (`), located at the upper-left corner of your keyboard. Below is a selection of commands you can enter. Square brackets (like [this]) indicate that you should replace it with the indicated value. In the case of [0|1], replacing it with a 0 will disable the setting; replacing it with a 1 will enable it. Note that some commands are considered cheats and will not work unless you enable cheat mode first by using the following command:

sv_cheats [0|1]

Doing so will disable all further story progress and achievements for this game session. During co-op, only the person playing as ATLAS can enable cheats.

Environment

These commands change how the environment behaves:

sv_portal_placement_never_fail [0|1]

When enabled, you can place portals on all surfaces.

sv_allow_mobile_portals [0|1]

When enabled, portals will continue to exist when the surface they are on moves, instead of closing as they typically would.

host_timescale [value]

Adjusts game speed. The value can be a number from 0.1 (1/10 speed) through 2 (double speed). Default value is 1.

sv_gravity [value]

Changes gravitational pull. A value of 0 creates a weightless environment. Default value is 600.

sv_speed_paint_acceleration [value]f

Sets acceleration when running on propulsion gel. Default value is 500.0.

sv_speed_paint_max [value]f

Sets maximum speed while running on propulsion gel. Default value is 800.0.

ent_fire prop_portal fizzle

Closes any existing portals, just as if you had walked through a fizzler.

sv_player_funnel_into_portals [0|1]
sv_props_funnel_into_portals [0|1]

Enables/disables the portal funnel effect for players and objects, respectively. The portal funnel effect is observed when falling into a portal; it draws you towards the portal, making it less likely that you'll miss it. There was an option for this in the game's interface in Portal 1, but not in Portal 2; the portal funnel is always on unless you use this command.

Spawns

The following console commands spawn new entities in the game:

ent_create_portal_weighted_cube	weighted storage cube
ent_create_portal_companion_cube	companion cube
ent_create_portal_reflector_cube	pivot cube
ent_create_portal_weighted_antique	old Aperture-style cube
ent_create_portal_weighted_sphere	edgeless safety cube
ent_create prop_monster_box	Frankenturret
npc_create npc_portal_turret_floor	turret
ent_create npc_personality_core	Wheatley
prop_dynamic_create npcs/glados/glados_animation	GLaDOS (not animated)
ent_create_paint_bomb_jump	repulsion gel
ent_create_paint_bomb_speed	propulsion gel
ent_create_paint_bomb_portal	conversion gel
ent_create_paint_bomb_erase	water
ent_create env_portal_laser	laser
ent_create npc_security_camera	security camera
fire_rocket_projectile	Portal 1 rocket

Player Cheats

These commands give the player unfair advantages.

god

Invincibility (You can still die by falling into goo or a bottomless pit, however.)

buddha

Your health does not decrease when damaged

noclip

You are unaffected by gravity and can pass through objects and walls

notarget

Enemies cannot target you

Miscellaneous Commands

map [name]
changelevel [name]

Loads the named map. The difference between the two commands is that map will kick your co-op partner out of the game, while changelevel can only be used during co-op games and will not kick your partner.

crosshair [0|1]

Displays/hides the portal gun's crosshairs. Use this to take screenshots without the reticule being visible.

r_drawviewmodel [0|1]

Displays/hides the portal gun. (You will still be able to fire it.) Use this to take screenshots without the portal gun being visible.

thirdperson

Switches to third-person view.

thirdpersonshoulder

Switches to a third-person, over-the-shoulder view.

firstperson

Switches back to the normal first-person view.

r_portal_use_dlights [0|1]

When enabled, portals will emit a faint light.

portal_draw_ghosting [0|1]

By default, a "ghost" image of a portal is drawn when your view of it is obscured, allowing you to see where your portal is wherever you are. This is new to Portal 2; if you prefer it without ghosts like in Portal 1, disable this setting.

gameinstructor_enable [0|1]

When you disable this setting, the game will not give you any on-screen help prompts. Note that this includes the "speak" prompts at the beginning of the single-player campaign.

SINGLE PLAYER CAMPAIGN WALKTHROUGH

The walkthrough is organized into nine chapters, just like the game. Each chapter is broken into sections. Each time you encounter a load screen in the game, that will mark the start of a new section in this walkthrough. I've given each a descriptive label, followed by the name of the corresponding challenge map in quotes, if any. The first time an element or character appears, their name will be rendered in bold type.

Chapter 1: The Courtesy Call

In which you meet Wheatley, explore some of the old test chambers from the original Portal game, use the one-portal gun, and encounter an old enemy.

Relaxation Chamber and Old Test Chamber 00

(Old Test Chamber 00 is essentially the same as Test Chamber 00 from Portal 1.)

Obey the announcer voice and on-screen prompts. After awakening the second time, go to the door to answer it to meet Wheatley. Obey the on-screen prompts and enjoy the ride.

EASTER EGG
The first time you wake up, there is a painting on the wall showing a landscape and a cabin at daytime. When you wake up the second time, the painting has changed to a nighttime scene with the moon shown prominently. The mural on the wall also changes from day to night, and now shows a wolf howling at the moon. This is the first bit of foreshadowing about the end of the game.
END EASTER EGG

ACHIEVEMENT: Wake Up Call
You receive this achievement automatically here.
END ACHIEVEMENT

When the ride ends, step on out onto the glass, which will shatter and drop you into the old test chamber below. Wait for the portal generators to produce portals that will allow you to escape the cell. Go through, then walk around the vault, past the chamber sign and through the exit door. Pick up the cube under the dispenser and put it on the button, then go through the door and fizzler and into the elevator.

Old Test Chamber 01

(This is a modified version of Test Chamber 01 from Portal 1.)

Press the pedestal button on the right, then turn around and go through the portal. Pick up the cube and go back through the portal. Drop the cube and go hit the pedestal button on the left. Pick up the cube, go through the portal, and put it on the floor button. Go back through the portal and press the middle pedestal button. Go through the portal once more and through the door.

Old Test Chamber 02: "Portal Gun"

(This is a modified version of Test Chambers 02 and 03 from Portal 1.)

Walk down the stairs and to the pedestal. The floor will collapse, but you'll be okay. Walk forward to encounter a Rattmann den. Take a minute to enjoy the paintings, then walk up the ramp to pick up the one-portal gun. Shoot a portal at any of the nearby panels and walk through. Head up the inclined catwalk.

EASTER EGG
Douglas Rattmann has illustrated the events of the creation of GLaDOS in this den, but if you look up, you'll also see a drawing showing phases of the moon. This is another allusion to the end of the game.
END EASTER EGG

After some walking, you'll see another orange portal. Shoot a portal at an adjacent wall and walk through. Turn left and shoot a portal next to the door, then go back through the orange portal.

Old Test Chambers 03 and 04: "Smooth Jazz"

(These are modified versions of Test Chambers 04 and 05 from Portal 1.)

Note the orange portal near the button, then stand next to the pit. The dispenser will drop a cube in the pit. Place a portal under the cube. Go back to the orange portal, pick up the cube, and put it on the button. Head for the exit.

In the next room, note the two elevated platforms. One has an orange portal next to it, and the other holds a cube. Look down into the pit to see another cube. Drop a portal under it. Now you have a cube on each platform. Jump into the pit and go through the portal. Pick up the cube and toss it off the platform to the ground. Shoot a portal on the wall behind the other cube. Turn around, go through the portal and pick up the cube. Put both cubes on the buttons to open the door.

EASTER EGG
It's tricky, but you can trap yourself in this room. Instead of going through the door, shoot a portal through the door, then pick up the cubes and stack them, one on top of the other, next to the platform where the orange portal is located, on the corner of the button platform. Carefully jump up on top of the cubes, and from there up to the platform with the orange portal. Look over the edge and crouch down, and grab the top cube (which hopefully wasn't knocked to the floor). Put it through the orange portal and drop it. It will fizzle and, after some dialog from the announcer, the door will open.
END EASTER EGG

Head through the door, then look up through the glass ceiling to see another orange portal open. Shoot a portal at the wall and walk through. The glass will break, but you'll still be able to walk up and through the doorway.

EASTER EGG
If you enter the passageway on the right and go up the stairs, you will find a Rattman den, containing another moon drawing.
END EASTER EGG

Head for the door. If you're playing Challenge Mode, the finish line will be found here. They're always found at or near the end of the section, so subsequent finish lines will not be mentioned in this walkthrough.

Old Test Chamber 05: "Cube Momentum"

Shoot a portal at the floor and drop through. Shoot a portal under the dispenser in the corner. Push the pedestal button connected to the dispenser. The cube will land near you. Pick it up and put it on the button. Moveable panels will form stairs leading to the upper platform.

Go up the stairs and over to the two pedestal buttons. Shoot a portal on the inclined panel under the second dispenser. The left button releases a cube, while the right causes a large platform to pivot up for a brief time. Press the left pedestal button, then press the right one about two seconds later. This will cause the platform to pivot at the right moment to stop the cube from being thrown into the goo. If you miss and the cube goes into the goo, just try again until you get it. Go down to the lower level and get the cube, then go back up and put it on the button, then head for the door.

Old Test Chamber 06: "Future Starter"

Shoot a portal in a nearby wall to escape the pit you're in. Nearby is a deeper pit. Shoot a portal at the bottom and jump in. You'll be flung onto a platform near the exit door, which can be opened by the nearby button. However, if you get off the button, it closes again. You'll see a glass panel with a circular hole leading straight down to a cube. Shoot a portal through the hole under the cube. It will be tossed down onto the level below.

Drop down and shoot the portal at the bottom of the pit again. Grab the cube and jump into the portal while holding it. (Alternatively, you can drop it in first to see where it goes, then jump in and follow it.) You'll end up back on that platform, this time with the cube. Drop the cube on the button and head for the door.

The second part of this chamber is a more advanced version of the first. Shoot a portal on the inclined panel on your left as you enter. Jump into the pit and through the orange portal. You'll be flung over to the platform where the cube rests. High above the door you came in and to the left you'll see some concrete panels. Shoot a portal up there, towards the right-hand side. Grab the cube, and bring it with you as you jump through the orange portal in the pit. You'll be flung over the platform where the button is. Drop the cube on the button to open the exit door and raise a platform in front of it. Jump through the orange portal in the pit again to be flung up to the exit.

Old Test Chambers 07 and 08

When you walk into Test Chamber 07, Wheatley will hail you from Test Chamber 08 beyond a broken wall. Shoot a portal at the wall behind him and jump into the orange portal to join him. After some talk, Wheatley will detach himself from the rail. (Unfortunately, the game won't let you catch him, even if you try.) Pick him up and plug him into the socket that appears from the wall. Turn around so that Wheatley can do his thing, then pick him up and walk through the door he opened. Ignore the Oracle Turret and keep going. You'll meet him again later.

GLaDOS's Chamber

(This is the same chamber in which you fought GLaDOS in Portal 1.)

Eventually, you'll arrive at the familiar hallway that leads to GLaDOS's chamber. Ignore Wheatley's reservations and go through the door at the end of the tilted gantry. Step over GLaDOS's shattered remains and walk around the right to the back of the room. Walk past the incinerator and down the stairs. Jump down, then continue on into the breaker room. Plug Wheatley into the socket and enjoy the cinematic.

ACHIEVEMENT: You Monster
You receive this achievement automatically here.
END ACHIEVEMENT

The Incinerator and Old Test Chamber 19: "Incinerator"

(This is a modified version of Test Chamber 19 from Portal 1.)

Walk along the twisted metal structure. The chutes will move out of your way as you approach. Continue until you find the two-portal gun. Pick it up when GLaDOS uncovers it.

You're now standing at the bottom of what was the flame pit in Test Chamber 19 in the first game. You're now going to traverse the chamber in the opposite direction. Start by portaling up to the upper hallway in front of you, then portal past the broken wall. GLaDOS will provide an inclined panel. Use it to portal up to a higher platform. Go around the bend and portal up to another higher platform. Shoot a portal through the broken window to enter the room with all the broken, hanging panels. Walk past the Test Chamber 19 sign to the elevator.

Chapter 2: The Cold Boot

In which you start using the two-portal gun in earnest, GLaDOS gets off a load of passive-aggressive lines, and you may just catch a few glimpses of someone you thought you'd never see again.

GLaDOS Test Chamber 01

(This is a modified version of Test Chamber 06 from Portal 1.)

Cross the chamber and stand on the victory lift in the water. (Don't worry, it's shallow.) Turn around and face the entrance. GLaDOS will shortly replace the energy pellet emitter and receiver with ones for a laser beam. Shoot a portal at the panel lying on the floor to your right, below the emitter so that the beam strikes it. Look for a faint red glow on the ceiling on your left. Shoot your other portal at that point. The beam should strike the receiver, which will activate the lift and raise you to the upper level. Head for the exit.

ACHIEVEMENT: Undiscouraged
You receive this achievement automatically here.
END ACHIEVEMENT

GLaDOS Test Chamber 02: "Laser Stairs"

Turn to the left as you enter. You'll see a pivot cube on the far side of the room. Drop a portal under it, then place another portal anywhere on your side of the barrier to transport the cube over to you. Pick up the pivot cube, then place it in the laser beam so that it is redirected to the receiver. This will activate panels which will form stairs allowing you to access the upper level.

EASTER EGG
During this part, you might notice Wheatley peek out at you from the wall in the area where the pivot cube was. If you're at the right place at the right time, you may be able to grab him before he retreats back into the wall. However, he won't interact with you, and even if you bring him with you into the elevator, he'll be gone when you arrive at the next chamber. It is possible that the developers did not anticipate people being able to grab him.
END EASTER EGG

Go up the stairs, then shoot a portal on the floor next to you. Drop the other portal under the pivot cube. It will oscillate between the two sides of the portal. Grab it while it's on your side an drop it on the button to open the exit.

GLaDOS Test Chamber 03: "Dual Lasers"

EASTER EGG
He's hard to see, but Wheatley is briefly visible underneath the mechanical arms which are raising up the platform in the center of the room.
END EASTER EGG

EASTER EGG
In one corner of this room is an opening in the wall. Go through it to find another Rattmann den. There's a radio in here which plays "Exile Vilify," a song written especially for Portal 2 by The National.
END EASTER EGG

As you enter, note the two pairs of laser emitters and receivers. Portal up to the platform on the left, the one with the laser receiver on the ceiling above it. Drop a portal on the floor below the receiver, then shoot the other portal at the spot on the wall that the upper laser strikes. This will activate the ceiling receiver. Grab the pivot cube, then jump over to the central platform. Place the cube in the beam so that the laser is redirected to the other receiver. This will open the door; jump down and head out.

GLaDOS Test Chamber 04: "Laser Over Goo"

Shoot a blue portal at the center panel of the wall on your left as you enter. Make sure to step to one side of the platform so that you're not standing in front of the blue portal. Shoot an orange portal at the spot on the wall where the laser beam strikes. The laser will be redirected to the receiver and the unstationary scaffold will start to move.

Aim your portal gun at the wall next to the pedestal button across the goo moat. When the scaffold has moved over to that part of the room, shoot the orange portal at that wall. This will disrupt the laser beam, causing the scaffold to stop. Enter the blue portal to go over to the other side of the moat. Press the button and watch out for the falling cube. Pick it up and step onto the scaffold.

Drop the cube at the center of the scaffold. Making sure to stand on the side of the cube away from the laser emitter, place the orange portal back on its previous spot so that the laser beam is redirected and the scaffold begins to move again. When the cube interrupts the beam, the scaffold will stop. Walk around the cube to the other side of the scaffold, then pick up the cube and pull it out of the beam. The scaffold will move again. When the scaffold reaches the other side, hop off and drop the cube on the button to open the exit.

GLaDOS Test Chamber 05

Step on the aerial faith plate to be catapulted to the other side of the room. Press the pedestal button to cause the dispenser in the middle of the room to release a cube. It will bounce up and down continually on the middle faith plate. Step on your faith plate at the same time as the cube hits the middle plate and grab the cube in mid-air. When you land back on the entrance side of the room, step on that faith plate again, still holding the cube. Both you and the cube will be shot over to the exit. Drop the cube on the floor button to open the exit.

GLaDOS Test Chamber 06: "Trust Fling"

Turn left as you enter and walk to the far side of the platform. Note the faith plate on your right as you pass. Turn to your right and look for two angled panels. Shoot a blue portal on the nearest one and an orange portal on the far one. Go back and step on the faith plate. You'll bounce off two more plates, pass through your portals, hit one more plate, and land on a platform on the opposite side of the room.

ACHIEVEMENT: Final Transmission / EASTER EGG
Look back towards your portals. On the wall on the left, you'll see two rows of concrete panels. Zoom in and shoot the orange portal on the furthest panel away on the second row. Move over to the pedestal button and press it. A bunch of trash will be released from the dispenser, bounce off the faith plates, pass through your portals, and land in an opening in the opposite wall.

Portal back over to your starting platform, walk over to the far edge, and replace your portals exactly as you set them up before to fling the junk in the opening, with the blue one on the closer angled panel and the orange one on the rightmost panel on the second row of concrete panels on the far wall. Go back and step on the faith plate. You'll end up in a Rattmann den where some of the junk landed.

Look for a radio and pick it up. Walk around the den until the radio starts making strange noises. This will award you the "Final Transmission" achievement. The noises are an SSTV signal which, when decoded with the appropriate software, produces a picture of a Companion Cube on the moon. This is the third allusion to the end of the game.

The den also features more drawings by Douglas Rattmann, including more images of phases of the moon.
END ACHIEVEMENT / EASTER EGG

ACHIEVEMENT: Pturretdactyl (chance #1)
A broken turret will have landed either in the den or on the platform outside. Once you've found it, portal back to the starting platform with it. Drop it on the faith plate to earn the "Pturretdactyl" achievement.

After earning the achievement, set up your portals as you did in step 2. Step on the faith plate and land on the far platform.

Note: If you can't find the turret, it might have fallen into the goo. No problem, you can get this achievement in a later chamber, or try this chamber again.
END ACHIEVEMENT

ACHIEVEMENT: Drop Box (chance #1)
Look above the floor button on the left to see a concrete panel on the ceiling. Shoot the orange portal on that panel. Press the pedestal button. This time, a cube will be dropped, bounce off the faith plates, pass through your portals, and land on the floor button, awarding you the "Drop Box" achievement and opening the exit door. Sometimes the cube will fall off the button, but as long as it was activated for at least a moment, you should get the achievement. If not, you can restart the chamber, or just leave the achievement for later.
END ACHIEVEMENT

If the cube fell off the button, you can just press the pedestal button to fizzle it and try again, or you can shoot a blue portal nearby and go through it, then pick up the cube and drop it on the button. The last faith plate is close by, so you can jump on it to return to the exit platform. With the exit door now open, head through to the elevator.

GLaDOS Test Chamber 07: "Pit Flings"

Hop over the laser beam and pick up the companion cube. GLaDOS will fizzle it the instant you pick it up, just to jerk your chain. She'll drop another companion cube from above; grab it. Try to interrupt the laser beam with it; GLaDOS fizzles that one as well and drops a third one.

EASTER EGG
Wheatley once again briefly peeks out from the wall, and it's possible to grab him. He appears by the victory lift shortly after GLaDOS fizzles the second companion cube. As before, he won't interact with you, and he'll disappear when the next level loads if you bring him with you in the elevator.
END EASTER EGG

GLaDOS lets you keep the third companion cube. Pick it up and drop it in the laser beam to disrupt it. A victory lift will lower.

Get on the lift, then shoot a blue portal under the companion cube. Shoot the orange portal on the wall next to the laser receiver. The receiver will reactivate and the lift will take you up. Up here there are two angled platforms, one across from a button and the other across from the exit, which is on a higher level than the button. Shoot the blue portal on the platform across from the button. Look down below and shoot the orange portal under the companion cube to bring it up to you.

Pick up the cube, then jump into the orange portal from above to fling yourself over to the button. Put the cube on the button to open the exit. Move the blue portal to the other panel, then jump into the orange portal. You'll be flung up to the exit. GLaDOS points out that the fizzler across the exit door is broken and tells you not to bring anything with you. Note that there are some concrete walls past the broken fizzler. There's an Easter egg and an achievement that use those walls; if you're not interested in them, just walk past them to the elevator.

EASTER EGG
You can trap yourself in this chamber. Move the blue portal on the concrete wall past the broken fizzler. Drop down to where the companion cube is, pick it up, then drop all the way to the bottom level. Drop the cube into orange portal, then move the blue portal down here. After some insults from GLaDOS, she'll fizzle the cube and drop another, at which point you have to start from the beginning and solve the chamber as before.
END EASTER EGG

ACHIEVEMENT: Preservation of Mass
To get this achievement, follow the same instructions as for trapping yourself above, but instead of dropping the companion cube through the orange portal to leave it by the exit, go through the orange portal with the cube. Pick it up and carry it toward the elevator. GLaDOS will fizzle it, but you'll get the "Preservation of Mass" achievement.
END ACHIEVEMENT

GLaDOS Test Chamber 08: "Fizzler Intro"

EASTER EGG
GLaDOS speaks what she claims is an explanation for this chamber in extremely rapid speech. Slowed down, it's actually a quotation from the first paragraph of the Herman Melville classic "Moby-D​i​c​k": "...and methodically knocking people's hats off—then, I account it high time to get to sea as soon as I can."
END EASTER EGG

Walk up the steps and through the fizzler. Press the pedestal button to drop a pivot cube on the other side of the fizzler. Shoot a portal on the wall through the circular hole in the glass. Shoot the other portal in the wall near you. Go through the portal and pick up the pivot cube, then bring it back through the portal to the other side. Drop the pivot cube in the laser beam so that the beam passes through the fizzler and activates the laser receiver. Head for the exit. (You don't need your portals anymore, so you can go through the fizzler if you want.)

Chapter 3: The Return

In which you get to have a few brief chats with Wheatley once more, you encounter fully-functional turrets for the first time, and GLaDOS continues insulting your performance, weight and alleged status as an orphan.

GLaDOS Test Chamber 09: "Ceiling Catapult"

Step on the faith plate three times. You'll get brief snippets of conversation with Wheatley, interspersed with snarky comments from GLaDOS about your weight. After this, GLaDOS will lower the ceiling, cutting you off from Wheatley. Shoot a blue portal at the newly-lowered ceiling. Further ahead, you'll see concrete paneling on the ceiling, over the upper platform. Shoot an orange portal on that. Step on the plate to land on the platform.

Walk into the little room on the left. It contains a laser emitter and two upper platforms, one with a pedestal button and one with the corresponding dispenser. There are also angled panels facing each. Shoot an orange portal at the panel facing the button. Jump through the orange portal to land on the faith plate and get shot back through and up to the pedestal button. Press it to release a pivot cube on the other side. Move the blue portal to the other angled panel. Jump through to hit the plate and be rocketed up to the pivot cube. Take it and jump down.

Place the pivot cube in the laser beam so that it leaves the room and strikes the barrier. Note that there is a laser receiver on the other side of the barrier. As you exit the small room, there will be an angled panel on your left. Shoot the orange portal at it. Jump through to hit the faith plate and be shot up to the upper level where the exit door is. Shoot a portal on each side of the barrier to let the laser beam pass through and strike the receiver. This will open the exit door.

GLaDOS Test Chamber 10: "Ricochet"

As you enter, turn around and shoot a blue portal high up on the wall above the entrance door. Turn back around and head for the pit in front of you. Shoot an orange portal into the bottom and drop into it. You'll be flung over to a ledge. Pick up the cube here and jump back into the pit without falling into the orange portal. Now that your velocity's been stopped, drop into the orange portal.

Hop onto the faith plate. You'll be shot up into a barrier and land on a ledge. There's a laser emitter here. Drop the cube in the beam to block it, causing the barrier to lower. Look directly in front of you to see a concrete panel on the wall. Shoot a blue portal at it. Jump down and step on the faith plate. You'll now be rocketed past the barrier, hit another faith plate on the wall, and run into another barrier on a second, higher ledge. Note a concrete panel to your left here.

EASTER EGG
You can trap yourself in this room. Shoot a blue portal into the concrete panel, then turn left and drop down to the cube. Grab it and drop from the ledge to the ground level. Drop the cube and shoot the orange portal under it so it falls through and is left up on the upper ledge. Now move the blue portal. GLaDOS will express some annoyance at your trapping yourself, and drop a pivot cube from the dispenser overhead, allowing you to solve the test again in a similar fashion to the solution described in this section.
END EASTER EGG

On the upper ledge, turn left and shoot an orange portal into the concrete panel there, opposite the laser receiver. Next to the orange portal is a pedestal button. Press it, then turn around and face the wall with the faith plate that shot you up here. After a moment a pivot cube will come flying up. Grab it. Drop down to the level below and replace the regular cube blocking the laser with the pivot cube. Aim the beam through the blue portal until it strikes the receiver. This will lower the upper barrier.

Pick up the regular cube, drop down to the floor, and step on the faith plate. This time, you'll be shot past both barriers and onto a ledge where the exit door is found. Drop the cube on the nearby button to open the exit door, and head through.

ACHIEVEMENT: Overclocker
Complete this chamber in 70 seconds or less to get this achievement. Here's a pro tip for shaving off a few seconds: As you're flying through the air approaching the platform with the exit, toss the cube to the right so that it lands on the button as you land on the platform. This saves you from having to walk over to it to drop the cube on it and walk back.
END ACHIEVEMENT

GLaDOS Test Chamber 11: "Bridge Intro"

As you enter the chamber you'll see an emitter projecting a hard light surface. Get on it and shoot a blue portal at the point where it strikes the wall.

EASTER EGG
Behind the panel where you shot the blue portal is another Rattmann den. Upon entering, a panel will move to reveal Wheatley moving along a rail behind the wall, before being covered up again. There's also more moon phase drawings on the wall.
END EASTER EGG

Look to the left and you'll see a chasm, on the other side of which is a pedestal button and the exit door. Shoot an orange portal on the far wall to form a hard light bridge across the chasm. Cross to the other side. (Note that you can do this by walking across the bridge or by simply entering your portal.)

Press the pedestal button. Notice the dispenser behind the glass on the left continually dropping cubes into the goo. To the right of the dispenser you'll see a passageway, but there's no floor. So we'll make one: walk out onto the bridge to the point where you're lined up with the passageway. Face the opposite wall and shoot an orange portal onto it such that it reorients the bridge to pass under you and into the passageway.

Enter the passageway on the bridge. At the end, turn left to see another concrete panel on the wall. Shoot an orange portal on it to form a new bridge there. Walk to the next corner, where there's another panel on your right. Shoot an orange portal there to move the bridge again. Now the cube should land on the bridge, or at least let you get close enough to catch one. With cube in hand, walk back through the orange portal to end up on the entrance side of the chasm.

Opposite the dispenser is an alcove containing a button. Shoot an orange portal on the wall opposite this alcove so that the bridge goes into it. Go through the blue portal, walk into the alcove, and drop the cube on the button to open the exit door. Try to do it while staying on the bridge if you can, but if not, no big deal; just walk out to the ledge and shoot the orange portal anywhere that will form a bridge near you that you can jump onto from the ledge.

Walk through the orange portal to go back to the entrance side of the chasm. Shoot an orange portal on the far wall to form a bridge all the way across. Cross to the opposite side, either on the bridge or through the portal, and go through the exit.

ACHIEVEMENT: Bridge Over Troubling Water
You receive this achievement automatically here.
END ACHIEVEMENT

GLaDOS Test Chamber 12: "Bridge the Gap"

After a brief conversation with Wheatley, enter the chamber and look to your upper-left to see a hard light bridge with some concrete panels near it. Shoot a blue portal up there and an orange portal into the wall at the end of the ledge you're on. Walk through and stand on the light bridge.

EASTER EGG
Look up to see a hole in the ceiling. Portal up there to enter another Rattmann den, featuring more moon phase imagery. Once you're done looking around, simply jump into the goo to restart at the beginning of the room.
END EASTER EGG

Shoot a blue portal into the wall where the light bridge ends to extend it through your orange portal. Walk through. Turn left and face the dispenser, and drop the orange portal into the wall at your height, so that the bridge extends under the dispenser and leads back to the ledge where you're standing. (You'll notice a tiled panel at the appropriate spot.) The bridge should pass just slightly over the ledge so that it crosses the room and strikes the wall above the alcove where the exit is located.

Press the pedestal button and make sure the cube lands safely on the bridge. If not, adjust the orange portal's position and try again. Then go out on the bridge and pick up the cube. Turn around and walk on the bridge past the ledge and out over the goo on the other side. Stop and put the cube down on the bridge. Turn around to shoot an orange portal through the hard light bridge onto the side of the ledge. This will lower the bridge and cause you and the cube to drop down onto it and extend the bridge into the exit alcove. Walk down the bridge and jump into the alcove, drop the cube on the button, and head for the exit.

GLaDOS Test Chamber 13: "Turret Intro"

This chamber marks your first encounter with fully-functional turrets. The first one you find faces away from you; simply pick it up and toss it to the side. The second one is around the corner, this time facing you. Before going around, shoot a blue portal into a nearby wall. Then quickly turn the corner, shoot an orange portal behind the turret, then pull back again. Go through the blue portal to arrive behind the turret. Pick it up and toss it.

Around the next corner is a third turret. The wall behind it won't accept a portal, but the ground it's standing on does. Pop around the corner and drop an orange portal under the turret to dispose of it. Further on you'll find two turrets behind glass. However, they're guarding the next passageway so you need to get rid of them. Note that you have a clear shot at the ceiling above each, which accepts portals. There are also some cubes nearby. Place one portal above one of the turrets, and drop the other under a cube. It will fall on top of the turret and knock it out. Repeat with the other turret. (If you haven't gotten the "Drop Box" achievement yet and want to get it here, don't pick up any cubes. Don't feel like you must, though; you can get it automatically later.)

The room containing the exit door contains three turrets. One faces you as soon as you enter, another faces the exit, and the last stands in front of the exit. Peek around the corner and drop a portal under the one in front of the exit. You can do this without exposing yourself to fire. The other two don't stand on portal-accepting surfaces, but the ceiling above will take portals. Peek around the corner and quickly stick a portal on the ceiling over the far turret, the one trying to lock onto you. Duck back around the corner and go back to one of the cubes. Pop the other portal under it to drop it on top of that turret. The only turret remaining faces away from you, so walk right up to it, pick it up and toss it aside.

ACHIEVEMENT: Drop Box (chance #2)
Note: You don't have to get this achievement here. If you've already got it or want to get it later, you can just pick up the cube and stick it on the button. Otherwise, put a portal over the button and the other under one of the cubes. The cube should drop onto the button and award you the achievement.
END ACHIEVEMENT

GLaDOS Test Chamber 14: "Laser Relays"

This chamber contains three laser relays. Take the nearby pivot cube and place it in the beam so that it passes through the two relays which are closer to the door. Shoot a portal at the place in the wall being struck by the laser. Shoot the other portal at the wall near the remaining relay. Adjust the portal as needed until the laser activates the relay. Head for the exit.

GLaDOS Test Chamber 15: "Turret Blocker"

Right off the bat, you'll see four turrets facing you. Fortunately, they're blocked by a hard light wall. A visible aiming laser informs you, however, that a fifth turret around the corner remains unblocked. Shoot a blue portal at the point where the hard light bridge hits the wall. Go around the corner and quickly shoot an orange portal at the wall next to the turret so as to block it with another wall. Walk right up to it, then move the portal and quickly grab the turret before it can fire. Toss it away.

Facing into the next room, you'll see a pillar with concrete panels at the bottom. Shoot the orange portal into the side facing you so that it forms a wall to your right as you enter the room. This will protect you from a cluster of four turrets on the other side.

ACHIEVEMENT: Pturretdactyl (chance #2)
If you haven't already gotten this achievement, you can get it now by grabbing the turret you tossed aside earlier (or any turret you can get a hold of in this chamber) and dropping it on the faith plate.
END ACHIEVEMENT

Head over to the faith plate on the left and look across in the direction it shoots. You'll see a platform up above, and across from it is a concrete panel. Put an orange portal on that panel so that the wall crosses above the platform. Step on the faith plate. You'll be tossed into the hard light wall and land on the upper platform. Walk along the glass until you reach the opening that leads down to the four turrets and a cube. Drop down in there and knock out the turrets.

Take the cube, then drop down and walk up to the button. As soon as you drop the cube on it, the glass wall blocking the turrets in front of the exit will drop. Quickly shoot a portal behind them, then duck behind one of the pillars to the side to avoid getting shot. Shoot the other portal on a nearby wall.

EASTER EGG
You can trap yourself in this chamber if you remove the cube from the button before walking through the portal. (You could also just stand on the button to lower the glass instead of having put the cube on it.) Once on the other side of the glass, move the portal you entered to a nearby wall. After GLaDOS dispenses some more pithy comments, she lowers the glass wall, letting you back out.
END EASTER EGG

With the cube on the button, walk through the nearby portal to end up behind the turrets guarding the exit. Dispose of them if you like, then head for the exit.

GLaDOS Test Chamber 16: "Laser vs. Turret"

As you enter, you'll see a grate on the right wall with a turret behind it. Don't stand idly in front of it; move straight into the room. The glass hallway is full of turrets. Shoot a blue portal at wall facing into the hallway, and put the orange portal on the floor under the laser emitter. Stand on the button and watch with glee as three turrets are destroyed by the laser!

EASTER EGG
Move the blue portal to the adjacent wall, so that the laser will fire into the room instead of down the hallway. Take the two cubes out of the hallway. Put the regular cube on the button to fire the laser. Hold the pivot cube and use it to aim the laser into the grate you passed on the way into the chamber and destroy the turret inside. This will also knock out the grate. Crouch to enter the vent. Look down into the opening to see four turrets "serenading" another, larger turret. Further in is another Rattmann den. Go back out when you're done looking around.
END EASTER EGG

Move the orange portal so that the laser strikes the floor again. Take the pivot cube and aim the laser through the glass to destroy the remaining turrets. Aim the laser through the glass at the receiver, then put the pivot cube down. Go through the glass hallway to the exit.

GLaDOS Test Chamber 17: "Pull the Rug"

As you enter, you'll see a hard light bridge with a cube on it at the upper-left. Turn around and shoot a blue portal at the point where it hits the wall. On the right is a concrete panel at ground level. Shoot an orange portal there. Walk through to arrive where the cube is.

EASTER EGG
Above the orange portal you'll see more concrete panels near the ceiling. Move the orange portal to the topmost one directly above its current position. Looking through the blue portal, you should see the bridge now passing into an opening in the wall. Enter the blue portal and continue into the opening. You'll encounter another Rattmann den. This one contains some of the same art found in the den in chamber 11, as well as a new piece of art with more moon images. If you do this while developer commentary is turned on, there will be a commentary node here. Activate it to hear strange noises. (Like the one found with the "Final Transmission" achievement, this is an SSTV signal, this one producing slides talking about the production of the Portal 2 ARG.) Walk back out on the bridge and through the orange portal. Interestingly, the Rattmann den is now blocked off and any portals you may have placed inside have been fizzled.
END EASTER EGG

Turn to the right to see a laser receiver. On the wall to the right of the receiver is a concrete panel. Shoot an orange portal onto it. Take the cube and pull it out of the laser beam. You'll see a lift ascend on the other side of the room. Walk through the blue portal and drop the cube on the bridge so that it interrupts the beam, directly above the red button. The lift will lower once more. Drop to the ground and stand on the lift. Move either portal so that bridge holding up the cube disappears. The cube will drop, restoring the laser and raising the lift you're standing on. It will then land on the button, unlocking the exit.

Chapter 4: The Surprise

In which GLaDOS finishes her reconstruction work and really starts being a jerk with the orphan jabs, and you and Wheatley finally start turning the tables on her.

GLaDOS Test Chamber 18: "Column Blocker"

After experiencing GLaDOS's "surprise," proceed through the door and jump through the window into the chamber. Note that beyond the hard light wall is a turret. It's behind a grate, meaning you won't be able to lob anything at it. There are three sources of cover: the alcove at your left (which has a laser emitter in the ceiling above it), the glass wall at the right, and the hard light wall. In a pinch, you can shoot a portal at the ceiling where it hits and the other portal at the floor in front of you to provide cover wherever you're standing.

Behind and to the right of the turret is an area out of the turret's field of vision. Shoot a portal in the wall over there, and shoot the other under your feet. The button here will release a pivot cube from each of the two dispensers. However, they bounce off of faith plates and collide in mid-air, falling into the goo. Shoot a blue portal at the point in the ceiling struck by the light wall. Shoot the orange portal on the floor directly in front of the far dispenser. This should form a wall between the dispensers. Press the button. The pivot cubes will both end up on the other side.

Move the orange portal to a nearby panel and walk through. This will dump you back behind the hard light wall. Put the blue portal in the wall behind the alcove on the left, where the laser emitter is. Put the orange portal under one of the pivot cubes to dump it into the laser alcove. Move the second pivot cube into the alcove in the same way. Then move the orange portal under your feet to join them. Pick up one of the cubes and place it so that the beam strikes two of the four laser relays. Take the remaining pivot cube and step out into the open with it. Quickly put the cube in the laser and aim it at the turret to destroy it before it fills you full of bullets.

Pull it out of the beam to reactivate the two laser relays. Walk past them to the far corner of the platform and turn to your left. You will see the other two laser relays and the laser receiver in a line. Use the pivot cube to redirect the laser to pass through the relays and hit the receiver, opening the door. Shoot a portal at the ceiling where the light bridge hits, and shoot the other on the outside wall of the alcove to form a bridge that passes in front of the door. Step onto the bridge and cross to the exit.

GLaDOS Test Chamber 19: "Laser Chaining"

Upon entering the chamber, look across and down and notice the faith plate in the floor of a small alcove on the opposite wall. There is also a pivot cube on the floor. Look to your upper-left and you'll see another pivot cube on a ledge. Look to your right and you'll see a third pivot cube on another ledge. We'll need to get these two cubes down from their ledges. The one on the right is easier, so we'll start with that one.

Jump down to the floor, then shoot a portal on the ceiling directly above the pivot cube. Shoot the other portal anywhere you can reach nearby and hop in. Grab the pivot cube and bring it with you to the ground. Put it down. Face the remaining pivot cube. There are concrete panels on the wall to the right of the cube. The panel you're interested in is the upper-left one, right in the corner of the room. Remember that panel.

Turn around and face the alcove with the faith plate. On the ceiling above it is a blue bull's-eye. Shoot the blue portal there. Face the panel the corner you noted earlier. Now face down and shoot the orange portal on the floor in front of you. Face the panel again, then walk forward and drop into the orange portal. You'll hit the faith plate and be shot back through your portals and high in the air. While in the air, shoot the BLUE portal at the panel in the corner. You can take your time; you will continue to be shot into the air until you shoot the portal. When you do it right, you'll be thrown onto the ledge where the pivot cube was, knocking it to the ground. If you end up standing on the ledge, jump down to the ground. (Note that sometimes the cube will end up knocked into the alcove where you came in. If that happens, leave it there. It will save you a step later.)

Now that we've got all three cubes, it's time to use them. Look up at the laser beam and notice that it goes into an alcove on the same side of the room as the entrance door. Portal up there with one of the pivot cubes. Look across the room and you'll see a laser relay. Place the pivot cube on the floor of the alcove such that it redirects the beam into the relay.

Jump down to the floor and shoot a blue portal at the bull's-eye above the faith plate. Shoot an orange portal on the floor. Grab a pivot cube and drop it in the orange portal to send it bouncing into the air. Look towards the alcove where you left the first pivot cube. To the right of it you'll see more concrete panels. While the cube is in the air, shoot the blue portal at those panels. Watch the pivot cube fly out of it and make sure it ends up in the opposite alcove.

Now you need to follow the cube. Move the blue portal back above the faith plate, hop in the orange portal, then shoot the blue portal at the same panels. If you do it right, you'll end up in the same alcove. Pick up the pivot cube and look across the room. You'll see another laser relay in an alcove on the other side. (It's the one with the entrance door. Notice that it has a concrete panel ceiling.) As before, use the cube to redirect the beam and activate the second relay. This opens the exit door, but we can't get to it yet.

Jump down, then shoot a portal into the ceiling of the alcove with the entrance door, where we've redirected the laser beam. Shoot the other portal anywhere nearby. If it isn't already up there, grab the remaining pivot cube and bring it with you through the portal. Use the cube to redirect the laser beam and destroy all the turrets standing by the exit. Then aim it at the laser receiver to the left to raise a platform near the exit. Hop back down to the floor.

Remember that panel in the corner we had to fling out of to knock down the pivot cube earlier? Look up at it again. Just to the left of it, on the other wall, you'll see more concrete panels. Put a blue portal above the faith plate again and shoot an orange portal at the floor. Face the panels you just noted, walk into the orange portal, and shoot the blue portal at the panels while in mid-air. You'll be flung onto the platform you raised earlier. Head for the exit. Whew!

GLaDOS Test Chamber 20: "Triple Laser"

As soon as you walk in, turn to your right. You'll see three laser receivers on the wall, connected to the exit door. Opposite them is a pillar. Shoot a blue portal onto that pillar so that it's pointed directly at the middle receiver. Walking back out, you'll see three laser emitters: one in the ceiling, one in a wall, and one in an angled panel. The laser from this last emitter is striking a panel; shoot an orange portal at it to activate a receiver.

Grab one of the pivot cubes and place it in the beam from the laser emitter in the ceiling. Aim it through the orange portal to activate another receiver. Grab the remaining cube and stand directly in front of the orange portal, behind the laser beam from the emitter in the wall. Use the cube to redirect that beam through the orange portal, activating the final receiver. Head for the exit. That wasn't so hard!

GLaDOS Test Chambers 21 and 22: "Jail Break"

Shoot a portal at the panel the light bridge hits. Turn around and find the pedestal button on the wall. Shoot the other portal at the panel to the right of the button, forming a bridge which crosses in front of it and which passes under the dispenser. Get on the bridge, go through the portal, and press the button to drop a cube on the bridge. Walk towards the cube, and the power will suddenly go out and you'll fall to the ground. Wheatley will appear at the left; walk over to him. After a moment he'll open a passageway. Follow him; GLaDOS will kill you with neurotoxin if you stick around.

ACHIEVEMENT: SaBOTour
You receive this achievement automatically here.
END ACHIEVEMENT

Continue following Wheatley until GLaDOS extends a light bridge to you and offers an escape route through Test Chamber 22.

ACHIEVEMENT: Good Listener
Take the bridge into Test Chamber 22. GLaDOS was lying, of course, and she'll kill you with neurotoxin. No worries, though; you'll get the achievement and be back here in seconds.
END ACHIEVEMENT

Ignore GLaDOS's offer and proceed along the light bridge away from Test Chamber 22. She'll cut the bridge out from under you and you'll land on a catwalk. Turn around and run the other way until the loading screen appears.

"Escape"

Continue following Wheatley. Eventually you'll walk into an area with a number of pneumatic tubes. GLaDOS will trap you inside and deploy three turrets in the area. Immediately duck behind a tube for cover. Walking carefully around the tubes, you should be able to approach the turrets one by one outside of their field of vision. Pick each one up as you reach it and toss it. Once all the turrets are dispatched, look around until you find a concrete wall. Drop a portal on that wall. Behind it, beyond the panels trapping you, is another concrete panel. Shoot the other portal there, then go through to escape.

Follow Wheatley. GLaDOS will open a wall at your left, revealing another turret. Simply drop a portal under it to dispatch it and keep going. You'll reach a part where GLaDOS starts moving the walls, trying to crush you. Hurry! The catwalk to the left leads to a door, but it gets knocked out. Keep moving forward and take the next left. Run straight ahead and don't stop until you're in the lift.

Chapter 5: The Escape

In which you do most of the work sabotaging GLaDOS's weapons while Wheatley blathers uselessly (and hilariously), you defeat GLaDOS again (surprise, she's still alive), Wheatley goes off the deep end, and you take a dive.

"Turret Factory"

Portal past the partially opened door. Proceed onward to find Wheatley. GLaDOS will turn the lights off on you, but Wheatley will provide a light. Continue following him. If you get confused about where you should be going, check to see where Wheatley is shining his light.

You'll soon encounter a stopped conveyor belt with miscellaneous parts on it. Hop on, move along it, and exit on the left. After a few more turns, you'll jump down to the bottom of some stairs. At the top, Wheatley will have you jump down onto a moving conveyor belt. Watch out for passing metal sheets. Stand on the metal sheet on the conveyor belt just before the one being worked on by the cutting lasers. When the lasers stop and move towards you, quickly walk past them and move onto the catwalk on the left.

Walking amongst a bunch of pneumatic tubes, you'll eventually arrive at an apparent dead end, with the catwalk leading straight up to a wall. Look up and to the left to see an upper passageway; portal up to it. In this passageway is a window opening into darkness. Wait a moment and Wheatley will light up a wall. Portal over to it. Repeat with the next one he shows you.

Follow Wheatley as he guides you past the turret assembly machines. You'll come up to a tall room with several pneumatic tubes. Drop down onto the metal boxes below, then walk along the tubes until you reach the blue floor. Head into the hallway and through the round door.

Turret Testing Area: "Turret Sabotage"

You'll enter a control room; drop a blue portal here. Continue onward to a conveyor belt. Above one end you'll see a concrete wall. Put your orange portal there, then walk through the blue portal to land on the conveyor belt. Just before the furnace, there is a metal platform on the right. Step onto it, then walk on top of the ductwork and onto the second conveyor belt. Walk against the direction of travel.

ACHIEVEMENT: No Hard Feelings
As you move up the conveyor belt, a malfunctioning turret will speak up, saying "I'm different." This is the Oracle Turret we saw back in Chapter 1. To get the achievement, pick up the Oracle Turret.

If you keep holding it, it will say some interesting things which foreshadow later events in the game:

WARNING! MAJOR SPOILERS AHEAD!

• "Get mad!" and "Don't make lemonade!": A reference to Cave Johnson's "combustible lemons" rant in Chapter 7.
  
• "Prometheus was punished by the gods for giving the gift of knowledge to man. He was cast into the bowels of the Earth and was pecked by birds.": This is a reference to GLaDOS. In Chapter 6, having been placed into a potato battery, she falls with you into the old Aperture Science facility deep below the surface of the earth, and is later pecked by a bird.
  
• "It won't be enough.": Uncertain. Some possible references include:
  
  • A morality core isn't enough to control GLaDOS, referencing dialog in Portal 2: Lab Rat: Doug: "What is that thing anyway?" Henry: "Just the latest in in AI inhibition technology. You can think of it as a conscience." Doug: "If that's all you use to control her, it won't be enough." Henry: "Why not?" Doug: "You can always ignore your conscience."
    
  • Removing GLaDOS from power is not enough to allow Chell to escape (Chapter 5)
    
  • Wheatley's addiction to testing and the diminishing rewards he experiences from solved tests (Chapter 8)
    
  • The plan to fry Wheatley using paradoxes (conceived in Chapter 7, attempted in Chapter 8)
    
  • GLaDOS's experiences in the game not being enough to change her, as she claims to delete Caroline (Chapter 9)
• "The answer is beneath us.": A reference to old Aperture Science, in the salt mines deep below the modern Aperture facility. You and PotatOS spend Chapters 6 and 7 there, where you learn of GLaDOS's origins and forge your alliance against Wheatley.
  
• "Her name is Caroline. Remember that.": In Chapter 7, you discover that the mind of an Aperture Science employee named Caroline was uploaded into an artificial intelligence, resulting in the creation of GLaDOS.

END ACHIEVEMENT

At the other end of the conveyor belt, step off onto the support beam, then carefully drop down onto the catwalk. Past a fizzler, you will encounter the firing range. Stop and listen to the hilarious defective turrets for a while if you like, then portal into the firing range, behind the wall. Listening to the turrets will tell you whether the turret that's at the firing range is defective or not. If it's defective, you're safe to step out from behind the wall for a moment. Shoot one portal into the bull's-eye side of the target wall. Shoot the other at the wall behind the turret line. When you're clear, go through. Don't hang around, as turrets can shoot you through the portal.

Next is the turret scanning room. Take a minute to see what's going on here. Before each turret is scanned, the scanner sweeps over a turret standing in the control room. This turret is a template, against which the turrets on the production line are being compared. Defective turrets get tossed into the nearby incinerator. Stand in front of the incinerator and wait for a defective turret to come your way. Catch it, then continue along the catwalk to the control room.

Wheatley's waiting for you here. Put down the turret, then turn around when asked and Wheatley will break the glass into the control booth.

EASTER EGG
You can place portals in such a way to let you watch Wheatley "hack" the door; i.e. break the glass with his body.
END EASTER EGG

Portal into it and remove the template turret. Toss it away and it will explode.

ACHIEVEMENT: Scanned Alone
Stand inside the scanner where the template turret stood and allow yourself to be scanned to earn this achievement.
END ACHIEVEMENT

Exit the booth, grab the defective turret, then go back into the booth and stick it in the scanner. Now the functioning turrets get tossed and the defective ones are kept! Stand at the round door in the control room and wait for Wheatley to open it for you. Proceed down the catwalk and through the doorway. Turn left, pass through the office space and into the next hallway, where you'll find a bunch of potato batteries (and one baking soda volcano) from "Bring Your Daughter to Work Day."

EASTER EGG
Look closely at the one with the giant, overgrown potato. The poster has two legible items on it of interest: "special ingredient from Dad's work" and "by Chell." So apparently, Chell's father worked for Aperture Science and brought her to "Bring your Daughter to Work Day," and she's been trapped there ever since. Also, you'll see evidence here of Aperture Science's blatant disregard for safety: look up to see a neurotoxin pipeline passing right through the area where the "Bring Your Daughter to Work Day" science fair was being held.
END EASTER EGG

Follow Wheatley through the hallway, down the stairs and through the round door.

Neurotoxin Generator: "Neurotoxin Sabotage"

Walk along the catwalks past the neurotoxin generator and through the round doors. Continue into the lift. Upon reaching the top, turn to the right to see a laser beam cutting panels being carried along the manufacturing lines. Near you is a button; press it to stop the panels and open the nearby door. Once the panels drop out of sight, shoot a blue portal at the point where the laser strikes on the wall. Now go through the door.

Wheatley will go into a room on the right. You can stay for a while if you want and listen to some funny dialog. Continue on to a balcony overlooking the neurotoxin generator. On the left you'll see panels moving slowly upward. As soon as you see one appear at the bottom and start rising, shoot an orange portal on it. This will bring the laser beam into the room and cut half of the supply conduits. (Note: This is the only place in the game where a portal will not fizzle when the surface it is on moves.) If you don't get all four on that side, just keep shooting orange portals on the panels as they appear. Turn to the right to see panels being transported along the ceiling. Shoot the orange portal at those panels to cut the other four lines. When all eight lines are cut, go back and head into the room where Wheatley is. You'll be sucked into one of the pneumatic tubes. Enjoy the cinematic.

Pneumatic Tube Ride

This is just a cutscene. There's nothing to do here but listen to Wheatley during your ride through the pneumatic tubes.

GLaDOS's Chamber

Head up the stairs and into the hallway. The round door doesn't work, but GLaDOS's chamber is visible from the hallway on the left. A flickering light shines on a panel in the distance. Drop a portal on it, then place the other nearby and go through. Open the door. GLaDOS traps you and transports you into her chamber. After she fails to kill you with turrets, she brings in a tube through which she intends to pump in neurotoxin to kill you, but Wheatley tumbles out instead. Pick him up, and after a moment a socket will appear. Plug him in.

After a few moments, a room will open up with a pedestal button (called the stalemate button) in it. GLaDOS will use movable platforms to try to prevent you from entering. Just in front of the platforms is a strip of panels, and two of the walls in the stalemate button room have panels on them. Portal into the room using those panels. GLaDOS still has a ring of platforms blocking you from the button. Portal from one side of the room to the other, allowing you to reach the button before GLaDOS can get her panels in the way. Press the button and watch what happens to GLaDOS.

ACHIEVEMENT: Stalemate Associate
You receive this achievement automatically here.
END ACHIEVEMENT

When Wheatley provides the lift, get in. Enjoy the cutscene.

EASTER EGG
When Wheatley attempts to demonstrate how smart he now is, he says "Estás usando esta software de traducción de forma incorrecta. Por favor consulta el manual." In Spanish, this means, "You are using this translation software incorrectly. Please consult the manual." This is an early hint that Wheatley is not as in control of the facility as he thinks.
END EASTER EGG

Chapter 6: The Fall

In which you have a chat with a spud at terminal velocity, discover old Aperture Science, meet a crazy dead man, and learn about the first type of gel.

The Shaft

Another cutscene. There's nothing to do here but listen to PotatOS as you fall down the shaft.

The Salt Mine: "Underground"

Walk through the debris until encounter a concrete wall in front of you. Use it to portal past the fence on your right. Upon emerging on the other side, look up and to your left to see another panel. Portal over to it. Walk through the opening in the wall and turn left. Continue until you come to another concrete wall. Use it to portal to the platform that you see above the fence on your right. Drop down from the platform onto the raised walkway.

Turn left onto another raised walkway and past the signs telling to you stay out, until you reach a wall with locked doors in it. The game hints that you might find zooming useful here. Look up and to the left to see a distant concrete panel near a catwalk. Shoot a portal there, then turn around and use the wall on the other side of the fence to portal over to it. As you descend, you'll see another concrete wall at ground level. Portal down to it. You are now on the ground on the other side of the locked doors. Drop down to the lower level and walk past more signs. Keep going until you find a lever in front of a giant vault door. Throw the lever and a gate will open, letting you proceed.

On the left and right of the vault door you'll see two control booths. Each contains a small button that operates the vault door, but both must be pressed within a few seconds of each other to do it. You can't get from one to the other fast enough on foot, so portal up to one of them, then set your portals so that you can pass quickly from one to the other. Press one button, then quickly go through the portal and press the other. Drop down from the control booth and head over to the opening vault door. Once it's open, a light will come on, revealing a much smaller door in the wall beyond it, and access gates will open. Go through the smaller door.

Alpha Pump Station: "Cave Johnson"

Go through the door and turn left onto the catwalk. Walk up the stairs at the end, then turn left and walk back the direction you came on the upper level. You'll encounter a broken door. You can't get through, but you can portal past it. Throw the lever to open the door. Look up and to the right to see an office area. There's a broken catwalk that leads to it. Further in the distance you'll see a high concrete wall; portal up there using the patch of concrete on the floor.

Walk halfway along the support structure at the left, then turn and face down. You'll see one portal in the floor; you'll jump into it in a moment, so reposition it if needed. Then look to the right and shoot the other portal in the slanted concrete surface you see there. Jump through the first portal to get flung up through the Aperture Science Innovators logo and onto the broken catwalk.

Enter the door and pass through the lobby to the door on the other side. You'll end up back outside the testing spheres, but this time you're up on a high catwalk. Jump across the break to land on the platform ahead of you, then get in the elevator and hit the button to go up. At the top, turn left and look down a little to see the broken catwalk near a door with the word "ALPHA" above it. This is your destination. At your left is a concrete wall, but off in the distance you can see some catwalks near three metal doors.

ACHIEVEMENT: Door Prize (1/2)
Portal up to the metal doors and activate the small panel next to each one. This will get you halfway to earning this achievement. Then go back through the portal to the elevator.
END ACHIEVEMENT

Zooming in on the metal doors, put a blue portal on the slanted part above them. Then turn around and go down one floor via the stairs. Look down the elevator shaft and shoot an orange portal at the bottom. Jump into it to be flung onto the broken catwalk near the ALPHA door. Go through the door. Head into the control room and throw the lever on the machine. When the gate opens, shoot a portal in the wall at the end of the catwalk. Look up and left to see the large blue ALPHA sign. Above it is a support structure. Portal up to stand on that structure. Look to your upper right to see a catwalk; portal up to it and exit the room. As you exit, you'll see a pipeline on your right. Walk along it to another catwalk. Walk through the fizzler and into the elevator.

Alpha Test Chambers 01 and 02: "Repulsion Intro"

Walk along the catwalk and through the fizzler into the first test chamber. Jump into the pit with the blue repulsion gel and bounce across to the other side. Portal up to the platform on the left. Ignore the button for now. Across the room is another platform with a pedestal button. Jump into the gel pit; from this height you should be able to bounce over there. Press the button to release a cube. Jump down and get it, then bounce across the pit and go through your portal again. Drop the cube on the button to open the exit, then bounce across on the gel and go through.

As you head up the stairs, shoot a portal at the panels you see on the upper level. Turn left and use the wall there to portal up. Head to the left and drop onto the catwalk stairs. Go up and through the door into the next test chamber.

As you enter, look to the left to see a moving gantry near an alcove with a cube in it. Also notice a couple of portal-accepting surfaces above the track. Walk onto the gel patch and jump up to the platform. Shoot a blue portal on the nearby wall and an orange portal onto one of the panels above the gantry track. Drop onto the gantry through the portal, ride it to the alcove, and take the cube.

Jump down, walk back onto the gel, and bounce up to the the platform where your blue portal is. Drop the cube, turn around, and shoot an orange portal at the wall at the platform across the room, where the button is. Take the cube through the portal and place it on the button. This flips a panel on the wall so that it can accept a portal. Shoot a blue portal at the newly-flipped panel. Portal through and bounce off the gel to land on the other side.

Walk through the fizzler, then jump against the blue gel on one of the walls. Bounce back and forth between them until you reach the other side. Take the cube, return to the previous platform, and drop the cube on it. This flips another panel in the first room. Go back through the fizzler and look to your upper left to see the new flipped panel, directly opposite the exit door. Shoot a portal at it. Look down and left to see the first platform you bounced up to. Drop down onto it, then shoot the other portal at the wall. Hop through, bounce off the gel and land on the opposite platform. Go through the door and on to the elevator.

Alpha Test Chamber 03: "Bomb Flings"

(An odd name, as bombs don't appear until chapter 9.)

Drop down onto the platform below, then cross to the other platform by walking on the twisted metal support. Upon arriving at the other side, turn to your right and find the pillar that is closest to the elevator from which you emerged. At the top of that pillar is a catwalk with a concrete panel. Stick a portal up there, and use one of the ground-level panels on a pillar to teleport up to it. When you land on the catwalk, turn to the left and look down a bit to see a test chamber. Portal over to it.

The chamber has several platforms around at varying levels. Let's call the bottom level 0, and number them higher as they go up. At level 1 you'll see a lit panel; shoot the orange portal on it. Shoot the blue portal at the marked panel under the dispenser, then press the pedestal button and watch a gel blob land on the floor at level 1. The gel drips continuously, so you won't need to press the button again. Drop into the blue portal to move to level 1, walk onto the blue gel, and hop up to level 2.

Note the arrows on the ground pointing towards the exit. Stand between the arrows and look in the opposite direction. There's an angled panel behind a fizzler at level 3. Below that is a platform at your level. You are going to bounce across the gap and through the fizzler by painting a path of gel to it. To do this, put an orange portal on the floor at level 0, let a gel blob fly up, then move it to another spot so that the airborne blob splats onto the floor. Continue until you've painted a path across on level 0 and the floor at level two, below the fizzler. Move the orange portal out of the way so you don't fall into it, then jump across along the gel trail until you bounce off the level 2 platform on the other side and through the fizzler onto level 3.

Put the orange portal on the angled panel and watch the blue gel fly across the room and land past the arrows pointing at the exit. Walk to the side of the fizzler and look down at the floor at level 0. Shoot a blue portal down there and jump into it. You'll sail across the room, bounce off the gel patch and land at the exit.

ACHIEVEMENT: Vertically Unchallenged
You receive this achievement automatically here.
END ACHIEVEMENT

Alpha Test Chambers 04 and 05: "Crazy Box"

Chamber 04 is going to require a timed response, so take a moment to look things over. On one side of the room, there's gel dripping on the floor, a panel facing a grate, and a pedestal button high up on the wall. On the other side is a water flow and a higher platform. Shoot a blue portal under the gel drip, and shoot an orange one at the floor under the button. When the gel flies into the air, move the orange portal to the panel behind the grate so that it splats on the floor under the button. You will observe that the subsequent gel drips fly through the grate and land at the base of the water flow, getting washed out immediately.

Here's the timed part. Hop on the gel spot under the button and press it in mid-air. This will stop the water flow for a few seconds. Crouch so that when you land on the gel again, you don't continue bouncing. Quickly stand straight again and walk over to where the water flow was. Momentarily a gel drip will land there. Use it to hop up to the platform. Walk through the exit.

Look up to see high concrete walls with support structures near the ceiling. Portal up to stand on one of those structures. Look down and to the left, and shoot a blue portal on the angled panel. Shoot the orange one under the gel drip so that it paints the opposite wall. Look straight down and move the orange portal on the floor there. Jump into it to bounce off the gel patch on the wall and up to a higher platform. Walk through the fizzler.

This next area looks more complicated than it actually is. Go up the stairs around until you can look back down into the chamber you just left. Shoot a blue portal under the gel drip. Turn around and walk until you're standing under a marked panel. Looking across, you'll see an angled panel with a bright light shining on it. Shoot an orange portal on it. This will throw paint on another angled bit across from it. Look down to see a paneled floor below you. Shoot a blue portal there and jump in. You should bounce off the gel patch and land on an upper catwalk.

Walk around the right side of the pillar and look up to see a higher catwalk. Portal up to it, then follow it into the next test chamber. Save here. There's a suspended glass box containing a cube. Shoot a portal on the ceiling directly over it, then shoot the other portal under the repulsion gel flow. The box will get painted, bouncing around until it smashes its way out of the box.

ACHIEVEMENT: Schrodinger's Catch
When the box flies out, catch it before it hits the ground to get this achievement. If it hits the ground, reload and try again.
END ACHIEVEMENT

With the painted box in hand, put it under the water flow to wash off the gel. Then go place it on the button. This will lower a lift, but not all the way to the ground. Using the same technique you used in Alpha Test Chamber 03, paint the floor next to the lift, then bounce off the gel patch to land on the lift. Shoot the portal that's not under the gel dispenser on the ceiling above the cube. It will get painted and bounce off the button, raising the lift to the top. Head for the elevator.

Beta Pump Station: "PotatOS"

Emerging from the elevator, you'll see the exit lobby directly in front of you. Unfortunately, the door's blocked up. Heading back out to the catwalk, you'll see a concrete panel to the right. Drop a portal on it, then head back out to the catwalk and look to your right. There's a catwalk against a wall there. Portal over to it and go through the door.

Look high up in this room to find some catwalks. Portal up to them. Looking across the room, you'll see a small control room. Look down from the broken part of the catwalk to see two concrete patches on the ground. Shoot a blue portal in the closer one and an orange portal in the farther one. Notice that the orange portal orients itself perpendicular to the other one. This will cause you to face the wall opposite the control room when you come out of it. Jump into the blue portal and look up at the wall to see another concrete panel. Shoot a blue portal at it to get flung into the control room. You may have to try this a couple times to get it right.

Throw both of the levers in the control room, then go through the fizzler and out the door. Look up at the upper left to see a large control room and a smaller office above it with a catwalk leading to it. Portal up there. Directly across, through the circular Aperture logo, you'll see an elevator leading into the next testing sphere. However, it's blocked by a gate.

ACHIEVEMENT: Door Prize (2/2)
Walk into the office. In one corner you'll see a partially obscured door. Go through it into a hallway where you'll encounter three more vitrified doors. Activate the button panel next to each one to earn the achievement.
END ACHIEVEMENT

ACHIEVEMENT: Ship Overboard
Near the end of the hallway with the vitrified doors, you'll find one more door, this one blown open. Go through and look around. You'll see a dock and several life preservers with the name Borealis on them, but the Borealis herself is nowhere to be seen. This will earn the "Ship Overboard" achievement. Head out to the office and exit onto the catwalk.
END ACHIEVEMENT

Looking down from the catwalk, you'll see a patch of concrete on the ground; put a blue portal there. To the right you'll see an angled block of concrete; that gets an orange portal. Drop through the blue one to be flung up to the control room. Enter and you'll be hailed by PotatOS. She's in a nest in the glass control booth, being pecked at by a bird. Enter to scare the bird away, then pick up PotatOS.

ACHIEVEMENT: Tater Tote
You receive this achievement automatically here.
END ACHIEVEMENT

Picking up PotatOS will trigger the button underneath and open the gate blocking the elevator. Head back out to the catwalk and face it. Then turn to face the wall and look up. Place an orange portal as high up on that wall as you can, then turn and jump into the blue portal. You'll be flung over to the elevator.

Chapter 7: The Reunion

In which you encounter two more types of gel, endure much snark from PotatOS, learn the secrets of her past, and climb out of the salt mines.

Beta Test Chambers 01 and 02: "Propulsion Intro"

Take a moment to look at the items on your side of the chamber. You'll see a panel on your left, at the start of a track which leads to a ramp with a nearby button. There's also an elevated platform with a panel above it. Up on this platform is a pedestal button which activates a dispenser. This one drops orange propulsion gel rather than the blue repulsion gel you've been using thus far.

Put a blue portal on the panel facing the ramp, and an orange portal on the panel above the platform. Go through and stand on the grating. Shoot an orange portal at the panel below the dispenser, then press the pedestal button to spread gel along the track to the ramp. Shoot a blue portal at the panel on the ceiling above the platform, then hop down and stand at the start of the track. Run along it and up the ramp. You'll be propelled across the chasm and land on the other side.

In the hallway, you'll see arrows pointing right, but turn left and shoot an orange portal into the wall. Pass through to land back on the platform. Drop a blue portal under the dispenser and press the pedestal button. This spreads gel across the hallway. Drop through the blue portal, and keep running off the edge to land in a smaller hallway.

Upon turning left, you'll see a cube behind a pane of glass with a hole in it. Shoot one portal through the hole, then turn around and shoot the other at the wall. Go through, pick up the cube, and come back out with it. Portal back across to the gel-painted hallway, bringing the cube with you. Then portal across the chasm with it and drop it on the button near the ramp, which will raise it. Run down the track and off the ramp to land on a higher platform above the hallway.

On your right, you'll see a panel on the floor, and high above it is a pedestal button which opens the exit. Shoot a blue portal on the panel, then shoot an orange one on the panel facing the ramp across the chasm. Walk through and go slowly to the ramp, without jumping off. Turn around and run along the track back through the orange portal. You'll fly out the blue portal and into the air. When you reach the top, push the button to open the exit. You'll likely have fallen back through the orange portal and ended up on the other side again. If so, just run along the track and off the ramp to return. Walk through the exit.

ACHIEVEMENT: Portrait of a Lady
Behind the fizzler at the exit is a short hallway followed by another fizzler. On the left in this hallway is a gap, through which you can see a panel. Shoot a portal onto it, then use the panels on the right wall in the hallway to portal over there. Turn right and enter the small observation room there. Look at the painting on the wall to earn the achievement. Then go back through the portal.

(The painting portrays Cave Johnson and a woman. While the woman is not explicitly identified in-game, it is almost certainly Caroline. If you look closely at the background of the painting, you'll also see a robed figure. This figure is Aeschylus, the author of "Prometheus Unbound," another reference to Prometheus, as first mentioned by the Oracle Turret.)
END ACHIEVEMENT

The next test chamber contains both repulsion and propulsion gel dispensers. Across the chasm is a tower with a panel on it. Shoot a portal there and drop the other one under the orange gel dispenser. Press its corresponding pedestal button to paint a track of orange gel up to the edge. Above the edge is another panel. Put a portal on it, then put the other one under the blue gel dispenser. Push its button to make a splotch of blue gel at the end of the track of orange gel. Run along the track of orange gel and bounce off the blue gel to land on the tower.

Walk around it on the catwalk to see the exit. On the back side of the tower, you'll see a panel, and directly above it you'll find a higher catwalk with another panel. Put a blue portal on the lower one and an orange portal on the higher one to access the upper catwalk. Walk back around and shoot a blue portal on a panel over on the platform where the dispensers are. Go back through the orange portal to arrive back on that platform. Shoot a blue portal at the panel on the tower, then run along the track of orange gel as before. You'll fly through the portals and land on a catwalk leading to the exit.

Beta Test Chamber 03: "Propulsion Flings"

Walk down the stairs and look around. Nearby are two dispensers which alternately drop blue and orange gel. Beyond them on the right you can see a platform with two panels, one angled one above another straight one. Shoot a blue portal on the straight panel and an orange one under the orange gel dispenser to cover that platform with orange gel. We'll call this platform "the runway."

Drop into the orange portal to end up on the runway. Head to the end, then turn around to face the blue portal. Shoot the orange portal on the angled panel above it, then turn to the right and shoot the blue portal under the blue gel dispenser. This will cause the gel to fly over your head and paint a high metal plate behind you. Move the blue portal back to the panel directly in front of you, then run down the runway and through the portal. You'll fly out the upper one, bounce off the patch of blue gel, and land on a suspended platform with a cube on it.

If you look in the direction from which you came, you'll see two other platforms to the left. One is further away and up high. It is small and has a ramp, so we'll call it the ramp platform. The other is nearer and lower; it's divided into two sections. One of the sections contains a button which controls an arm holding a panel which is held above the other section. We'll call this the arm platform.

Take the cube and look down over the edge to see a platform below you. Hop down to it, then portal over to the arm platform, on the side with the button, taking the cube with you. Put it down there, but don't put it on the button yet.

Look to the left to see the runway platform and portal up to it. Looking back to the arm platform, put a blue portal on the panel on the floor of the platform, directly below the one held by the arm. Turn to the left and place an orange portal under the blue gel dispenser. This will splatter blue gel on the panel held by the arm.

Portal back over to the box on the arm platform and put it on the button. This turns the arm so that the blue-painted panel now faces up instead of down. That done, go back through the portal to end up on the runway again. Go to the end of the runway and face the two panels. Put one portal on the flat one in front of you, then turn a bit to your left and put the other one on the panel in front of the ramp. Run down the runway and through the portal. You'll launch off the ramp, bounce off the panel held by the arm, and land on the catwalk to the elevator.

ACHIEVEMENT: Stranger Than Friction
You receive this achievement automatically here.
END ACHIEVEMENT

Gamma Pump Station: "Conversion Intro"

Walk through the fizzler, turn left, and look up. You'll see a catwalk above you; portal up to it. (The exit lobby's elevator is non-functional, unfortunately.) Walk through the upper fizzler and notice the sign pointing towards the gamma pump station, high up on the wall. Portal over there and walk through the fizzler. As you enter the pump station, you'll see the control room directly ahead, and a catwalk leading to it on the left. Notice the pistons situated above the catwalk. Rather than walking over there, use the nearby panels to portal yourself into the control room. Activate all three levers, then use the portals to return, bypassing the now-active pistons.

You'll see a new, white gel flowing from an open pipeline. This is conversion gel, which makes any surface it paints accept portals. It has coated the underside of an overhead beam, and directly under that is a catwalk. Drop a portal on that patch of white gel and use it to portal up to the catwalk. Then jump down and bounce off the patch of blue gel to land on the small catwalk across from it.

Past the fizzler you'll see a trail of orange gel passing under a set of pistons. There's a panel in this area; drop a blue portal on it. Then time your run along the trail of gel so as to pass by the pistons without getting crushed. Head out the door. After scaring away the bird, drop an orange portal on the slanted panel on your right. Then go back inside, run under the pistons and through your blue portal to be launched over to a set of stairs leading up to an office area.

Walk through the office until you arrive at the portrait of Cave Johnson. Enter the door to the right of the portrait and press the button to open the exit door in the waiting room. Go back out and through the other door, through the waiting room and out the exit. Follow the catwalk to the elevator, which will take you to a new area.

Drop into the pen where the white gel is flowing. Put a blue portal under the gel flow, then put the orange one on another area painted by the white gel. The gel will fly out and paint more surfaces. Repeat as needed until you have coated a suitable surface outside of the pen, then put the orange portal on it and drop through the blue portal to get out.

Outside the pen, you'll find an angled metal plate. Move your orange portal around to paint the ground until you can coat that plate with gel. Nearby are two pillars, one of which has a high catwalk on it. Move your orange portal to paint your way over to there, then start painting the sides of the pillars facing each other. Continue moving the orange portal up the pillars until you've painted the wall above the catwalk. Then portal up to it.

Walk around the pillar and look down to see the slanted plate, now painted white. Put a portal on it, then another one on the ground nearby and jump into it. You'll be flung up to another platform, where you can follow the stairs to the exit. Enjoy a hilarious rant from Cave Johnson.

ACHIEVEMENT: White Out
You receive this achievement automatically here.
END ACHIEVEMENT

Continue walking until you reach the elevator to the surface. It's not working, and the elevator car is up above you. However, there are plenty of portal-friendly surfaces around, so use them to teleport your way up the floors until you reach the elevator car.

Drop a blue portal on the floor of the elevator car, then exit it and turn left to see a drop. Shoot the orange portal on the floor at the bottom of the drop and fall in to fling yourself higher up the shaft. As you reach the top of the fling, look around to find a portalable surface on the floor; shoot an orange portal at it. Don't worry if you don't get it on the fling; your momentum will cause you to continue flinging between your two portals, so feel free to take your time to get it right. Your new orange portal will cause you to be flung up higher, where you can see an angled panel. Shoot a blue portal at it to be flung onto a catwalk. Go through the door.

Journey to the Surface: "Three Gels"

As you enter the next room, look up and to the left to see a high catwalk. Note the slanted concrete area above the door. Now look at the four pillars in the middle of the room. There are two sets of crossbeams on them. The pillars are concrete, so use them to portal up and stand on one of the upper crossbeams. Shoot a blue portal at the slanted concrete above the door, then shoot an orange portal directly below you. Jump into it to be flung up to the platform.

There's a slanted metal plate here. Look behind you and off to one side to find some dripping blue gel. Drop an orange portal under the drip to paint the metal plate. Then move the orange portal back down to the floor below and jump in. You'll be flung onto the painted plate, bounce off, and land on the next level up.

Directly ahead and above you, you can see a room with dripping gel. That's where you're trying to go. Turn around and put and orange portal on the concrete on the ground near the back wall. Drop down to the level below through the hole in the platform, then jump down into your blue portal on the ground to be flung upwards. As you fly up, you'll see concrete on the floor of the topmost platform. Shoot a blue portal on it as you're airborne. When you're flung into the air above the top platform, move to the side so that you land on the ground. Proceed across the catwalk into the room.

At the top of the stairs, look straight ahead. There's a section of wall with an angled part above it. Look higher up to see a patch of concrete through a grating, directly above the angled part. Shoot a blue portal there. Put an orange portal under the white gel drip to paint that section of the wall. Move the blue portal to the flat part of the newly-painted wall, and move the orange portal under the orange gel. This will paint a track of gel along the floor. Move your blue portal up or down on the flat part as needed to get good coverage. Note the spot of blue gel near the end of your track, created by the drip above it.

Make sure the blue portal is at the upper part of the flat area, then put the orange portal on the slanted part. Run down the track, bounce off the blue gel, and fly through your portal to get flung to the upper platform. Here you bounce off another patch of blue gel, then land on some concrete. Shoot a blue portal into the concrete, then look through the grating in the platform floor to shoot an orange portal under the white gel drip. This will paint the ceiling above the portal. Move the orange portal to the newly-painted ceiling, directly above the blue portal. Shoot through the grate again to put the blue portal under the blue gel drip below. This will create a puddle of blue gel on the concrete.

Drop back down to the lower level. Put the blue portal on the upper part of the flat wall, and the orange portal on the slanted part above it. Run down the runway and bounce off the blue gel. You should get flung up, bounce off both puddles of blue gel, and land on a platform beyond. On the back side of the pillar is a blue gel drip. Look where it's coming from and you'll see a panel through the grate. Put a blue portal at the panel and an orange portal under the drip. Drop through the orange portal.

Walk through the short passage way and look up the shaft here. There are air vents all through this area. Nearby there's an angled panel behind a grate. Move the blue portal there. The gel will fly into an air vent and get sprayed all over. Use it to portal up to the highest part of the shaft you can reach. The shaft turns at an angle here; walk up it until you reach a grate. Look through it to find a concrete panel on the other side. Portal over to it.

In this new room, look up to see a high catwalk. Portal up to it. Walk along it until you reach a gap in the railing on the left. Turn to face it, then look up and right to see a high concrete panel. Shoot a portal there as high as you can, then shoot the other portal into the ground below and jump into it. This will fling you into a small gel pump station. PotatOS will call your attention to a sign on the wall. Look at it as directed. Then press the red button on the control panel. This will open the large hatch in the ceiling and connect three large pipelines, supplying gel to the modern Aperture Laboratories. It also lowers an elevator platform. Drop down to the floor and walk up the stairs to the lower catwalk to board the elevator platform and ride it up through the vault opening. Walk up the stairs and continue through to the elevator.

Chapter 8: The Itch

In which you first encounter excursion funnels, and solve a bunch of chambers being built on the fly by an unsubtle lunatic, while the entire facility threatens to blow itself up. Good times.

(For some reason, Wheatley has you solve two test chambers in a row numbered 01. In order to distinguish between the two, this walkthrough identifies the first one as 01-A and the second one as 01-B.)

Frankenturret Test and Wheatley Test Chamber 01-A

Proceed along the catwalks until you enter an observation room. You'll see a test chamber full of frankenturrets. A large monitor displays Wheatley, ranting at the cubes. There are 15 of these monitors in this chapter. The "Smash TV" achievement requires you to break 11 of them. The first four you encounter cannot be broken, but you don't need them for the achievement.

Part of the wall is broken in this room. Portal through there, then follow the catwalk to a short elevator. Ride that up, then continue until arrive inside the test chamber you just saw. Pick up any frankenturret and drop it on the button. Wheatley reappears on the monitor, but PotatOS's logic bomb fails.

EASTER EGG
When PotatOS attempts to fry Wheatley with the paradox, all of the frankenturrets in the room short out. Apparently they're smarter than Wheatley!
END EASTER EGG

Proceed through the door and past another monitor, then ride the lift into Test Chamber 01-A. There are two of Wheatley's monitors in this room, but neither can be broken.

ACHIEVEMENT: You Made Your Point
Wheatley will ask you to "solve" the test chamber by pressing the pedestal button. Just stand there and do nothing. After a short time, you'll be awarded this achievement.
END ACHIEVEMENT

Press the pedestal button to drop a cube on the button on the other side of the room and open the exit.

ACHIEVEMENT: Drop Box
If you haven't already got it, you receive this achievement automatically here.
END ACHIEVEMENT

Portal across and go through the exit. There's another unbreakable Wheatley monitor in the vestibule. Instead of letting you into the next chamber, Wheatley makes you go back and do the same chamber again. Complete it as before. The second time around, Wheatley allows you to proceed. You'll pass another Wheatley monitor on the way to the next chamber, but it, too, is unbreakable.

ACHIEVEMENT: Dual Pit Experiment
You receive this achievement automatically here.
END ACHIEVEMENT

Wheatley Test Chamber 01-B: "Funnel Intro"

Here you'll encounter your first excursion funnel, being projected from the emitter on the floor and passing through a hole in the ceiling. Jump into it, then look up and shoot a blue portal into the checkerboard-patterned panel where the funnel stops. When you pass through the hole, look over at the observation room and shoot the orange portal into the panel next to it. Ride the funnel to the end, where you'll find a frankenturret. Step out of the funnel and pick it up. Bring the cube down to the floor and put it down.

Looking through the hole through which the funnel passes, you should see a checkered panel on the floor below. Move the orange portal to that panel.

ACHIEVEMENT: Smash TV (1/11)
From now until the end of the chapter, every Wheatley monitor you encounter is breakable. You need to break all of the remaining monitors you encounter in chapter 8 for this achievement. Pick up the cube and hop into the funnel, stepping out of it after passing through the portal. Put the cube down, then shoot a blue portal at the ceiling and an orange one directly below it on the floor. Take the cube and drop it into the orange portal and it will start falling continuously through your portals. Move the blue portal to the top of the wall directly across from Wheatley's monitor, flinging the cube into the monitor and breaking it.

Shoot a blue portal at the checkered panel on the floor, then grab the cube and step into the funnel. Hop out again after passing through the hole.
END ACHIEVEMENT

Put the cube into the funnel, then move to the exit door. After a few moments, the funnel will push the cube against the button, opening the exit door.

Wheatley Test Chamber 02: "Ceiling Button"

As you enter, note the exit at the upper-left, then look down to see an excursion funnel. Drop into it. Face the panel you're moving towards and shoot a blue portal at it. Turn left and shoot an orange portal at the panels you see there. Pass through the blue portal. Exiting the portal, you'll see more panels on the left, and a checkered panel with lights next to it at the lower-right. Wait until you are in line with that panel, then shoot an orange portal at the panels on the left to move the funnel so that you end up directly above the checkerboard panel. Then shoot the orange portal at that panel to redirect the funnel upwards. When you reach the platform at the top, step out of the funnel and onto it.

Move the orange portal back to the earlier set of panels, so that the funnel passes horizontally over the checkered panel. Press the pedestal button to cause a frankenturret to drop into the funnel and move towards you. When it's over the checkered panel, move the orange portal to that panel to bring the frankenturret up.

ACHIEVEMENT: Smash TV (2/11)
Leaving the cube in the funnel, move to the edge of the platform so that you can see the panels directly across from Wheatley's screen. Shoot a blue portal at the top of those panels. This cuts off the funnel and drops the cube back into the orange portal, flinging it into the screen and breaking it. Put the blue portal back in front of the funnel, then repeat the previous paragraph to get a new cube.
END ACHIEVEMENT

Pluck the cube out of the funnel and drop it onto the nearby panel on the floor. Put an orange portal under it so that the funnel pushes it up into the button. This will open the exit and create a platform leading to it.

Wheatley Test Chamber 03: "Wall Button"

Note the inactive funnel emitter in front of you as you enter. Turn around and shoot a blue portal at the wall above the doorway where the funnel will strike when it's turned on. Shoot an orange portal at leftmost panel to the right of the exit door at ground level, facing the chamber Wheatley is smashing into this one. When he finishes with that, he'll activate the funnel; step into it to ride to the other side.

Step out of the funnel and turn so you're facing back the way you came. Put an orange portal on the panels on the left, so that the funnel passes directly under the dispenser. Press the pedestal button to drop a frankenturret into the funnel. There's another panel on the right that faces the platform you're standing on. When the cube comes in line with it, move the orange portal there to bring the cube to your platform. Move the orange portal to the panel left of the bull's-eye on the left so that the funnel passes directly in front of it. Take the cube and step onto the faith plate. You'll land in the funnel. Ride it until you can safely step out of it onto the other side.

ACHIEVEMENT: Smash TV (3/11)
Put the cube down onto the floor, then shoot an orange portal under it so that it is moved up to the ceiling. Shoot the blue portal on the wall directly across from Wheatley's screen. The funnel will cut out and the cube will be flung into the monitor. Move the blue portal back to where the funnel strikes the wall.
END ACHIEVEMENT

Directly across from the exit, there's a lone panel that has no portalable surfaces to the left or right of it. Put the cube down on the floor just below and in front of it, then drop the orange portal directly under it. Step in after it and ride the funnel up. When you come in line with the lone panel across from the exit, move the orange portal there to carry yourself and the cube to the exit. Step out of the funnel to drop onto the exit platform, leaving the cube in the funnel to press the button and open the exit door for you.

Wheatley Test Chamber 04: "Polarity"

As you enter, notice a turret aiming beam on your left. Quickly walk around the glass pane and to the the turret and pick it up. If you move fast, you'll only take a bullet or two before you get behind it, which Chell can apparently shrug off. Alternately, you can duck into the corner behind the glass and wait for it to give up searching for you, then hop back out and nab it.

ACHIEVEMENT: Smash TV (4/11)
Walk back out with the turret and gently put it down so that it's facing Wheatley's monitor. The turret will lock onto the monitor and shoot it out. Then pick up the turret again.
END ACHIEVEMENT

Toss the turret away, then look across to the other side. There's a frankenturret sitting out there. Shoot a blue portal at the point where the funnel strikes the wall, then shoot an orange one on the left wall on the other side so that the cube gets picked up in the funnel. Step on the button. The funnel reverses polarity, and the cube starts moving the other way. When it moves in front of the panels facing you, shoot an orange portal at them so that the cube is caught in the redirected funnel (but not yourself). Immediately step off the button so that the funnel gets reversed again and brings the cube to you. Pluck it out of the funnel when it arrives.

Put the cube on the button to reverse the funnel again. Step in and ride it across. Move the orange portal a little to the side so that it now passes directly over the button. This will pick the cube up off the button, reversing the funnel once more. Shoot the orange portal on the floor in front of the exit platform. Step in to be carried up, then step out and through the exit.

Wheatley Test Chamber 05: "Funnel Catch"

As you enter, note Wheatley's screen on the right. Shoot a blue portal where the excursion funnel strikes the wall, then shoot the orange portal on the single panel between the two faith plates. Step on the nearby faith plate to be catapulted into the funnel and raised up to the ceiling. Across from the exit is an angled panel. Shoot the blue portal there, causing you to fall and be flung up to the exit platform. After a moment, the wall will open and another monitor will appear over here.

Move the blue portal back to its original position, then press the pedestal button. A frankenturret will be released, which will bounce off the faith plate and get caught in the funnel, brought up to the ceiling as you were.

ACHIEVEMENT: Smash TV (5 and 6/11)
Move the blue portal to a panel across from and slightly above the first monitor you saw in this chamber. This one is a bit hard because you're not at a very good angle to see where it needs to be placed. If you positioned it correctly, the cube should strike the monitor and break it. If not, repeat the procedure to get and fling another cube until you get it. The spot you want will be just a bit to the left of the vertical shadow that falls across the panels, and on top of the lighter diagonal shadow crossing it.

Repeat the procedure again to get another cube. This time, shoot the blue portal at the right side of the angled panel across from the exit. The cube will get flung out of it, strike the monitor, and land on the platform where you are standing.
END ACHIEVEMENT

If you didn't do the achievements, shoot the blue portal on the angled panel across from the exit to get the cube flung over to you. Put the cube on the button to open the exit door.

Wheatley Test Chamber 06: "Stop the Box"

ACHIEVEMENT: Smash TV (7/11)
Step on the faith plate to hurl yourself into the monitor to break it.
END ACHIEVEMENT

Put a blue portal at the spot where the hard light surface strikes the wall. Put an orange portal on the upper part of the wall next to the fizzler. You want it roughly 2.5 rows down and as far from the fizzler as possible. Press the pedestal button, then quickly run to stand at the center of the ledge in front of the fizzler and catch the frankenturret when it bounces off the hard light surface.

Put the cube down and move the orange portal so that the hard light surface passes in front of Wheatley's monitor, just beyond the catwalk below it. Pick up the cube and step onto the faith plate. You should strike the hard light surface and land on the catwalk. Walk a short distance until you can see the turrets below to the left. Put down the cube and move the orange portal so that it redirects the hard light surface to block the turrets, allowing you to access the button in front of them safely.

Pick up the cube and follow the catwalk to the end, then drop down to the ground. Drop the cube on the button, which opens the exit door. Walk under the catwalk you came from so that you're out of view of the turrets, then portal back up to the catwalk using the panel here. Walk back along it and through the exit.

Wheatley Test Chamber 11: "Laser Catapult"

(Remember that Wheatley mentioned at the beginning of the last chamber that he was moving us closer to him. This caused us to skip to chambers 07 - 10.)

There's a frankenturret on the left on a high platform; let's get it. Shoot a blue portal under the excursion funnel emitter, then shoot an orange portal on the checkered panel on the floor near the faith plate. Step into the funnel to be raised up to the ceiling. Move the blue portal to the angled panel with the bull's-eye pattern on it. This will fling you up to the cube; grab it and bring it down with you.

Now we'll get the pivot cube, which is behind the funnel. Drop into the pit with the cube and put it down in the path of the laser. This deactivates the funnel. Portal out of the pit. Drop a blue portal on the angled panel facing the area where the funnel was, and put an orange portal on the bull's-eye panel. Step on the faith plate to be launched over to the pivot cube. Take it and drop down. Walk over to the laser and replace the frankenturret with the pivot cube so that the laser is aimed at one of the portal-accepting panels on the wall.

ACHIEVEMENT: Smash TV (8/11)
Shoot a blue portal at the spot where the laser strikes, then an orange portal at the wall across from Wheatley's monitor. Hold the pivot cube in the beam and adjust it such that it passes through the portal and strikes the monitor. Hold it there for a moment to break it.
END ACHIEVEMENT

Portal out of the pit, bringing the frankenturret with you. Drop it on the checkered floor panel, then shoot a blue portal at the spot where the laser strikes the wall. Shoot an orange portal at the panel across from the laser receiver near the lifts. This should activate the lower lift, bringing it to the ground. Step on the lift, then shoot the orange portal somewhere else so that the laser is disconnected from the receiver. The lift you're on will move up.

Shoot the orange portal under the pivot cube in the pit. This will move it out of the way, reactivating the excursion funnel. Put a blue portal under the excursion funnel and an orange portal under the frankenturret. This will raise it to the ceiling, pressing the button and lowering the other lift down to your level. Step on, then move the blue portal to cut off the funnel. This will raise the lift up to the exit.

Wheatley Test Chamber 12: "Laser Platform"

This chamber introduces the laser field, which is safe for objects but not for you. (Strangely, this is the only time the laser field appears in the game, aside from user-created chambers.) Notice that on the wall near Wheatley's monitor there are two panels where the left and right edges are divided into smaller squares. These are the two panels where we'll need to shoot our portals in order to strike the laser receivers on the opposite wall. Also notice a laser receiver connected to the exit door. Shoot a blue portal where the laser from the emitter strikes the wall, then shoot an orange portal at the lower marked panel. An unstationary scaffold on the other side will start moving slowly to the left.

When it reaches the left side, move the blue portal to the wall of panels near the dispenser. This will stop the scaffold. Walk through the orange portal to land on the scaffold. Stand on the side of the scaffold furthest away from the laser field, then move the blue portal back to where the laser strikes the wall. The scaffold will start moving towards the laser field. When the scaffold is halfway through the laser field, move the orange portal to the upper marked panel. This stops the scaffold and deactivates the laser field. Walk through to the other side of the scaffold, then move the orange portal back to the lower marked panel to start the scaffold up again.

When you reach the other side, drop down to where the pedestal button is. Let the scaffold move back to the other side. When it's under the dispenser, move the blue portal to cut off the beam and stop the scaffold. Press the pedestal button to drop a pivot cube on the scaffold, then portal over to it. Move your blue portal back to the panel struck by the laser beam.

ACHIEVEMENT: Smash TV (9/11)
Shoot an orange portal as far to the right of the upper marked panel as possible so that the laser beam passes over the scaffold. Pick up the pivot cube and use it to redirect the beam at Wheatley's monitor to break it.
END ACHIEVEMENT

Repeat the previous procedure to ride the scaffold safely through the laser field, bringing the pivot cube with you this time. When you're at the other side, move the orange portal to one of the panels to the left of the laser emitter above the exit door. Take the pivot cube and place it on the scaffold such that the beam strikes the laser emitter, unlocking the exit.

Drop down to where the pedestal button is. Portal over to the exit door, but it's closed again because we cut off the laser beam by moving our portals. Move the portals back to where they were before in order to reestablish the beam, then walk through the exit door. Hop into the excursion funnel, and Wheatley will eventually drop you into an office area. Go out the door, follow the catwalk, and jump down into the area revealed by the moving panels.

Wheatley Test Chamber 15: "Propulsion Catch"

(Our little adventure in the funnel just now caused us to skip a couple more chambers.)

EASTER EGG
Upon entering this chamber, Wheatley remarks that there's no exit, and so provides one by ripping apart an adjacent test chamber. Look closely near the exit and you'll see P-Body fleeing!
END EASTER EGG

Press the pedestal button to drop a frankenturret on the glass platform. Shoot a blue portal on the checkered panel on the ceiling, above the inactive excursion funnel emitter. Shoot an orange portal on the wall directly across from the cube. Step on the button to activate the funnel, which will pick up the cube. Shoot an orange portal on the panels under the funnel so that the cube will fall, get caught in the redirected funnel, and brought towards you. When it arrives, step off the button to cut off the funnel.

ACHIEVEMENT: Smash TV (10/11)
There are a number of ways to break this particular monitor. I find this one to be the most straightforward: Put a blue portal on the checkered panel above the emitter. Shoot the orange one the floor below the chamber sign. Grab the cube and put it on the button to activate the funnel emitter. Step into the funnel and ride it all the way up to the ceiling. Then shoot the blue portal into the panel located directly above the entrance door to fling yourself into the monitor.
END ACHIEVEMENT

In the corner is a small alcove with a button behind a pane of glass with a hole into it. Portal into it with the cube and drop it on the button. This will cause orange gel to be dispensed. Go back through the portal. Shoot a blue portal on the checkered panel on the ceiling, and an orange one on the panel below the observation window. Step on the button to activate the funnel, which will catch the gel. When the gel reaches the top of the angled floor plate, step off the button, which will drop the gel on the floor, forming a runway.

Walk behind the ramp at the end of the runway and look across the gap. On the right you'll see a fizzler, and behind it you can see a panel. Shoot an orange portal there so that the funnel is directed through the fizzler and over to the exit. Then run down the gel runway and off the ramp to land in the funnel and get carried to the exit.

ACHIEVEMENT: Tunnel of Funnel
You receive this achievement automatically here.
END ACHIEVEMENT

Wheatley Test Chamber 16: "Repulsion Polarity"

The hallway in front of you gets destroyed, and white gel is splashed all over. Use the gel to portal across the gap. Enter the chamber, but be careful of the three turrets on the right. Make sure you stay behind the glass whenever you're on this side of the chamber until you're able to dispose of the turrets.

Portal across the chamber. Put an orange portal on the back wall of the alcove where the dispenser is located, directly in line with it. Put a blue portal on the spot where the excursion funnel strikes the wall. This should cause the funnel to pass directly under the dispenser. Press the pedestal button to dispense some blue gel. Let the funnel carry it just a little bit forward until it passes over the solid part of the small platform where you are standing, then move the blue portal to cut off the funnel. This should drop the gel and paint that small solid area of the platform.

Move the blue portal back to its previous position to reestablish the funnel. Press the button, then quickly hop off the patch of blue gel and into the funnel. Ride it across to the other side, then quickly move out of it and step on the button, reversing the funnel. Let as much of the gel pass through the portal as you can, then shoot an orange portal on one of the two lit up panels above and to the sides of the turrets. At the same time, step off the button to reverse it, sending the gel back through the portal.

At the right moment, you need to move the blue portal so that the gel is dropped on the turrets, causing them to bounce away. If you're going to do the Smash TV achievement, you need to take out ONLY TWO of them; otherwise, take out all three.

ACHIEVEMENT: Smash TV (11/11)
Put the blue portal back to the point where the funnel strikes the wall. Put the orange portal on the floor so that the pillar at the left edge of the glass pane is between the funnel and the one remaining turret. In just a moment, you'll need to shoot the blue portal at the panel on the same side as the turret. Note that now, since you'll need to do it quickly. Stand behind the pillar until the turret gives up trying to find you.

Step into the funnel and ride it a short way up. Just before the turret opens fire, shoot your blue portal on the panel you noted earlier. You'll land on the platform next to the turret. Quickly pick it up before it shoots you, then walk back into the chamber with it and put it down carefully so that it's pointed towards the monitor. Once the monitor's been shot, pick up the turret and toss it away.
END ACHIEVEMENT

With the turrets out of commission, step to the other side of the glass and press the pedestal button. This reveals an angled panel on the wall. Go back around the glass and move the blue portal back at the end of the funnel. Put an orange one on the floor to direct the funnel up to the ceiling, then step in and ride it all the way up. Shoot a blue portal at the angled panel to get flung over, bounce off the blue gel puddle, and land at the exit.

Chapter 9: The Part Where He Kills You

In which Wheatley drops what little pretense of subtlety he had and goes completely axe-crazy, you learn how to lob bombs around, you meet three hilariously unstable personality cores, and Wheatley's lunacy becomes literal.

Wheatley Test Chamber 17

Step on the faith plate, which will fling you SIDEWAYS instead of forward as expected. Surprise! After a brief trip, you land on a small platform, with six monitors creating a giant image of Wheatley staring down at you. (None of these monitors are breakable, by the way.) You are also surrounded by crushers with unpleasant-looking spikey bits on them.

ACHIEVEMENT: The Part Where He Kills You
You receive this achievement automatically here.
END ACHIEVEMENT

If you stand around here for very long, Wheatley will activate the crushers and kill you. To the left of the monitors is a concrete panel, shoot a blue portal there. In a moment, white gel will start dripping onto a surface lower down. Shoot an orange portal there to cause gel to coat the platform you're standing on. Wheatley will freak out at this point and try to activate the crushers, so quickly shoot an orange portal under your feet to end up on a catwalk. (Note: The game is merciful to you at this critical point; if you shoot the wrong portal, it will switch the portals automatically.) Wheatley activates the crushers, but you're already gone. Follow the catwalk.

ACHIEVEMENT: Pit Boss
Wheatley will beg you to come back. Do as he asks. He'll be surprised by this, and realize that he doesn't have any way of killing you here, so he asks you to jump into the pit. Stay and listen for a while to some of the most hilarious dialog in the game, then jump into the pit. You'll be killed, but you'll get the achievement.
END ACHIEVEMENT

Go through the door and up the stairs. Continue until you arrive where the catwalk has been broken. Shoot a portal on the panel to the upper-right and the other on the panel directly below you. Jump in to be lobbed over to another catwalk. Continue onward. A crusher will narrowly miss you, destroying the catwalk in front of you. Shoot a portal on the wall at the other side, then back up a bit and use the wall there to portal yourself across. Go through the door.

Wheatley Test Chamber 75: "Finale 2"

As you move forward, Wheatley will move a test chamber across your path, destroying the catwalk. Part of the bottom falls away from the chamber, allowing you to see into it. PotatOS observes that this is probably a trap, but as there's no where else to go, portal inside the chamber using the concrete slab at the end of the broken catwalk. Wheatley attempts to ambush you with turrets, but they're defective. Dispatch them if you like, then jump out of the malfunctioning exit door and onto the catwalk below. Go through the door and keep going straight, as Wheatley guards the next section of catwalk on your left with turrets.

The room the turrets are in has an excursion funnel. Redirect it with portals so that the turrets are picked up and pass out the window. After they've all been removed, ensure that the funnel passes through the opening in the opposite wall, then jump in the funnel yourself.

EASTER EGG
Shortly before you move into the next room via the funnel, you'll pass over a catwalk. Step out of the funnel and land on it and see how Wheatley reacts. You can do this several times to get different reactions until eventually he stops talking in a huff.
END EASTER EGG

When the funnel has brought you into the next room, Wheatley opens a wall revealing spinning blades. When you get close, simply move out of the funnel to land on the ledge below.

Walk through the fizzler to find another funnel. Put a blue portal at the point the funnel strikes and an orange portal on the wall so that the funnel passes out the door. Hop in and ride it through, and Wheatley will deploy a crusher to kill you. Up ahead you'll see a panel move into place behind a catwalk. Move your orange portal to drop into a funnel moving you in the opposite direction, avoiding the crusher. (Note: Again, the game is forgiving at this point, and will automatically swap the portals if you shoot the wrong one, when technically it should just let you drop to your death.) Hop onto the ledge and continue onward through a door. A blue gel pipeline will fall and destroy the next catwalk, but fortunately it sprays its contents on the ledge in front of you. Use it to bounce across the gap. Put a blue portal on the panel on your right as you pass.

Don't advance too far into the next room or you'll get shot to pieces. Look up to see a window with the glass broken out. Shoot an orange portal through that window at the ceiling, then go back and go through your blue portal. Step on the button to start a blue gel drip. Put one portal underneath it, and the other on the large panel wall to the right of the turrets. Keep moving this portal around so as to hit all the turrets with gel. Then portal over to the faith plate in the room you're in and step on it to be catapulted over to a catwalk. Follow it and go through the door.

Bomb Transport Area: "Finale 3"

Upon entering the next room, put a blue portal on the panel above the window facing the conversion gel pipeline. Look out the window to see bombs being transported through pneumatic tubes. Shoot through the break in the window to drop an orange portal under the bend in the tube. Press the button. The tube will disconnect and turn downwards, throwing bombs through the portal and into the conversion gel pipeline in the room, spilling the gel on the floor. Move the blue portal onto the gel and portal over to the platform where the bomb pipeline was, then go into the control room and through the door.

Walk down the stairs and onto the conveyer belt. Walk towards the catwalk near the propulsion gel pipeline. Wheatley starts up the conveyer belt, activates a crusher at the end, and knocks out the catwalk you were going for. Turn around and ride the conveyer belt, then step off to the left before you're killed by the crusher. Put a blue portal below the bomb dispenser to the right of Wheatley's monitor.

EASTER EGG
It's possible to break the monitor here, though it isn't part of the "Smash TV" achievement. Simply put an orange portal in the middle of the panel across from the monitor and press the button to lob a bomb into it and see how Wheatley reacts.
END EASTER EGG

Put an orange portal in the middle of the panel across from the gel pipeline, then press the button. It will get shattered by a bomb and start leaking gel onto the platform. Put a blue portal under the gel flow and an orange portal on the panel at the end of the conveyer belt to coat it with gel. Wait for the gel to reach you, then hop onto the conveyer belt and run towards and through the portal to end up on the platform. Walk through the doorway and down the corridor.

In the next room, you'll find a dead-end hallway. Put an orange portal low on the end wall. This will paint the hallway with orange gel. Put the blue portal under the excursion funnel, then run down the hallway and through the portal to be flung into the funnel. Upon reaching the end, step out of the funnel to land on the catwalk. Follow it up and through the door. Portal upwards through the grate.

Wheatley's Lair: "Finale 4"

Hop up on the small ledge and look up. Shoot a portal on the panel you see high up the shaft, then drop the other under your feet to land in an upper passageway. There are a couple of bins full of personality spheres. Most are dead, but there are three active corrupted cores. You'll see them again shortly. Move on to the catwalk, and follow it to the elevator shaft. Plug PotatOS into the socket to be moved up into Wheatley's Lair.

Wheatley explains that he has watched footage of you beating GLaDOS (at the end of Portal 1), and has taken measures to avoid being defeated in the same way. First, the chamber contains no portal surfaces. Second, he starts filling the chamber with neurotoxin right away. (GLaDOS was unable to do that at the end of Portal 1 because she was initially inhibited by the Morality Core.) Lastly, he has altered GLaDOS's chassis, adding a bomb chute and shields on articulated arms. The countdown timer shows that you have five minutes before you succumb to the neurotoxin, presuming the bombs Wheatley's launching your way don't kill you first.

Wheatley throws the bombs in volleys of six, all landing at a spot he targets just before lobbing the first one. You'll hear a charging noise just before he starts throwing them. When you hear it, the spot you're standing on is the target. Just move away from that spot and you'll be safe.

You won't be able to fight back against Wheatley until you can get some portal surfaces to work with. Fortunately, a transparent conversion gel pipeline is visible on one side of the chamber. Go stand behind it and wait for the charging noise. (You can move there before he starts throwing bombs, while he's explaining how he will kill you.) The pipeline will burst when struck by a bomb, spewing conversion gel all over.

Wheatley arranges his bomb shields to protect him from strikes from below. Why? Because you can redirect bombs with portals, of course, and he expects you to place a portal below him to hit him with a redirected bomb. What he's failed to notice, however, is that there are some plates extending from the walls which also got gel on them. While there are several that can be of use to you, there is one in particular that is ideal: it hangs above the right end of the catwalk behind Wheatley. Put a blue portal on that panel, then place an orange one on the ground directly in front of you as you face Wheatley. When he starts throwing bombs, they'll drop into the portal and get redirected to him. This will temporarily stun Wheatley.

Drop into the orange portal to end up on the catwalk, where PotatOS has brought a corrupted core, the Space Sphere. It is obsessed with space and chatters about it incessantly. Grab the core, and the catwalk will collapse, breaking a repulsion gel pipeline. Note that there's a socket on the right side of Wheatley's chassis with a flashing red light on it. Bounce up there from a blue gel puddle; if you get close enough, the corrupted core will be attached automatically. Doing so disables the neurotoxin, but the reactor will still explode in four minutes.

Wheatley wakes up and finds (probably due to your plugging a corrupted core into him) that he can't turn off the bombs. This time, he raises his bomb shields so that he can't be attacked from above, but he's left exposed below. Move the blue portal directly under him and stand behind the orange portal as before to stun him with another bomb.

PotatOS brings another core, Rick the Adventure Sphere. In true Indiana Jones fashion, he swings back and forth between the two ends of the demolished catwalk. Move the blue portal back up to the panel above the catwalk. Drop into the orange portal, then jump off the broken edge of the catwalk and bounce off the repulsion gel to land on the other side. If you time it right, you can snatch Rick as you reach the apex of your bounce; if not, simply stand on the other side and wait for him to swing by to grab him. Rick starts talking when you grab him, and, in my opinion, he's the most hilarious of the three corrupted cores. Jump down and plug Rick into Wheatley as before, this time on his left side.

EASTER EGG
If you delay plugging Rick into Wheatley long enough, he'll ask you to get Wheatley to set him up for a cool one-liner. This will unlock an additional, funny bit of dialog later, shortly after you plug in the third core.
END EASTER EGG

The reactor explosion timer fails, but those nutty Aperture Science guys apparently made it so that in that case, the facility would pre-emptively self-destruct in two minutes. Great. Wheatley wakes back up and starts tossing bombs at you again. This time, he shields himself both above and below, but he does not have enough shields to protect his entire body, so he leaves his back exposed. Move directly opposite the blue portal above the catwalk so that Wheatley is directly between you and it. He will turn to face you, leaving his exposed back facing the panel. Move the orange portal if needed to be directly in front of you again, and let Wheatley lob a bomb into it to stun himself for a third time.

This time, PotatOS brings you the Fact Sphere on the other side of the chamber, held high above the ground. (Why can't she just drop it on the floor for you?) The Fact Sphere continuously spews a torrent of inaccurate trivia. It's far too high to reach using the repulsion gel, but a nearby propulsion gel line bursts, and the pipeline sprays a track of gel across the floor. Directly below the pipeline is a metal plate, coated with conversion gel. Shoot a portal into this plate, and shoot the other directly under the suspended core. Run down the gel track into the portal to fly up into the air and grab the core. Attach it to Wheatley as you did with the other two, this time on his front.

The self-destruct is averted, and PotatOS is raised into position for a core transfer. However, as before, the two cores are at odds and it's left to you to resolve the stalemate. A fire breaks out, but it's extinguished by a fire suppression system, which also washes away all the gel, except directly under Wheatley.

PotatOS tells you to press the stalemate button, but it's blocked by a grate. If you zoom in on the button, you'll also notice some bombs, which are hastily covered up by some moveable panels. Wheatley's booby-trapped the stalemate button. However, there's nothing else to do, so shoot a portal through the grate into the ceiling of the stalemate button alcove, then shoot the other under Wheatley and drop in. Wheatley sets off the bomb trap before you can press the button, throwing you across the room, but you're "still alive." Just before you regain control, your view pans up, and part of the ceiling falls away to reveal the moon.

Remember what Cave Johnson said about moon rocks? No? He said that he made conversion gel out of them because lunar soil is a great portal conductor.

SHOOT A PORTAL AT THE MOON! (Note: Technically you should shoot the one that is the opposite color of the one under Wheatley, but as before, the game is forgiving at this critical point and will automatically swap them if you get it wrong.)

Enjoy the closing cinematic.

ACHIEVEMENT: Lunacy
You receive this achievement automatically here.
END ACHIEVEMENT

UNLOCKABLE: Bionic Beanie
You receive this unlockable automatically here. Select "Robot Enrichment" from the main menu to equip the beanie on your co-op robot if you like.
END UNLOCKABLE

CO-OP CAMPAIGN WALKTHROUGH

In co-op mode, you will work with another person to complete courses together. You can play with any person in your Steam friends list who also has Portal 2, or you can ask the game to match you with a stranger. You will play as one of two robots. The blue one is of masculine programming, being of stouter frame and with a lower voice. His name is ATLAS and he's made from a personality sphere. His partner is P-Body. She is tall and lithe compared to her partner, and has a higher voice. She's orange and is constructed from a turret. GLaDOS will not acknowledge their names, simply calling them "Blue" and "Orange."

The puzzles will often have the two robots taking different roles when solving a puzzle. The robots are functionally identical, so it doesn't matter which robot takes which role. This walkthrough will distinguish the two roles by arbitrarily assigning one robot to each, but you can switch them if you want. The robots will be identified by the abbreviations B (blue) and O (orange). If a step does not indicate which robot is acting, both do it together.

Achievements will be mentioned in the co-op walkthrough when they can only be performed in a specific place, or when there is a particularly suitable spot to do so. The others can be performed nearly anywhere. See the achievements index after the walkthrough for the complete list.

The Ping Tool

The co-op robots have a tool that works kind of like a laser pointer. You can use it to briefly paint a surface or object with an icon that your partner can see. This is useful for giving instructions to your partner, since it's sometimes easier than trying to describe it, especially if you don't have voice chat. To use it, simply hold down the ping tool button to bring up a menu showing the available icons. Move the arrow towards the icon you want, then release the button. The ping tool is context sensitive; different icons will be available when pointed at different things:

Global pings (available at any time):

• Look here (eye)
  
• Countdown (stopwatch)
  
• Go here (person standing on bull's-eye)

Cube:

• Pick up (person holding cube)
  
• Put down (cube with down arrow pointing at target)

Button:

• Press (arrow pointing to button)

Portal surface:

• Place portal here (portal)

Portal:

• Enter (person entering portal)
  
• Exit (person exiting portal)

Note that the countdown ping compensates for lag, so it's better to use it to coordinate timed actions than voice chat.

Gestures

Gestures are mainly for celebration and goofing off, though they are required at one point in the co-op campaign, and are used for some achievements. You start with only one: wave. Over the course of the game, you'll unlock more: high five, laugh, paper/rock/scissors, hug, dance, tease and trick fire. Simply hold down the gesture button to bring up a menu showing the available gestures. Move the arrow towards the icon representing the desired gesture, then release the button. You can cancel the gesture by selecting the cancel icon in the center. There's also one additional gesture you can perform only while airborne; it will be executed immediately when you press the button. Additional gestures can be purchased as downloadable content.

Calibration Course

When you start a co-op game, the Calibration Course will be selected automatically if either player has not yet played it. Unlike other courses, you start out separated from your partner, so your roles are not interchangable.

The first part is a tutorial on how to use gestures and the ping tool. When prompted, use the gesture menu to wave to your partner, use your ping tool to select your favorite animal/element, and look at your partner's selection. You'll then be dropped into the start of the course. Wait for GLaDOS to finish talking, then use your ping tool to point at the slanted panel above the portal gun. GLaDOS will place a portal there. Now ping one of the nearby panels to get a portal there. Walk through to get the portal gun. When both partners have the portal gun, the doors will open. Go through them, then portal up to the ledge and go through the door.

O: Stand on the button.

B: Walk through the doors, then stand on the button.

O: Walk through the doors.

B: Move forward and portal up to the ledge.

O: Your partner's progress is blocked by a pane of glass. Shoot a portal on the wall on each side of that glass through the opening in the glass that is separating you.

B: Walk through the portal your partner made for you.

Continue through the fizzler. Press the pedestal button in front of you to drop a cube to your partner. Pick up the one they give you in return and place it in the cube receptacle to open the door for your partner. When they have done the same for you, go through the door.

O: Stand at the edge of the goo where the dispenser is.

B: Press the pedestal button.

O: Catch the dispensed cube, then toss it to your partner through the opening in the glass. Walk through the fizzler to the other side.

B: Take the cube to the other opening in the glass and toss it through.

O: Take the cube and put it in the receptacle. Head through the doors and stand on the button to deactivate the fizzlers.

B: Go forward until you see an opening in the glass on the left. Shoot a portal through that opening into the wall at ground level. Walk ahead to the next opening in the glass and shoot the other portal at the wall there.

O: Pass through the portal that your partner made for you, then drop down and press the pedestal button to raise a set of platforms to the dual door.

Walk forward on the raised platforms to the exit, then step into your robot's respective disassembly machine.

UNLOCKABLE: High Five Gesture
Upon both partners reaching the dual door, you will automatically perform the high five gesture. It will then be unlocked for both players in the gesture menu.
END UNLOCKABLE

UNLOCKABLE: Weighted Companion Cube Flag
The automatic high five also awards this unlockable for both players. Select "Robot Enrichment" from the main menu to equip the flag for your co-op robot if you like.
END UNLOCKABLE

ACHIEVEMENT: High Five
The automatic high five also awards this achievement for both players.
END ACHIEVEMENT

ACHIEVEMENT: Professor Portal
If you've completed the co-op campaign but this is your partner's first time
playing it, you'll earn this achievement at this point.
END ACHIEVEMENT

The Hub

The Hub is the area from which you can access any of the six courses. The first course starts out unlocked; the remaining courses are unlocked by completing the previous course. Any course unlocked by either player will be accessible. You can also replay the Calibration Course through an option in the game menu. To return to The Hub during a course, open the game menu and select the appropriate option. This walkthrough will assume you're pursuing the courses in order.

Course 01: Team Building

In The Hub, the door leading to Course 01 is on the left, below the giant status board. You'll see a course sign above it identifying it as "Team Building." Go through the door. Check the the chamber selector to make sure it's set to send you into the first chamber, then proceed to the dissasembly machines.

Chamber 01: "Doors"

B: Step on the button in the middle of the room.

O: Turn left to see another button in a small glass alcove. Next to that is a panel on the wall; shoot an orange portal into it. Now walk through the door.

B: Go stand on the other button, near the orange portal.

O: Walk out through the newly-opened door. Turn right and shoot a red portal in the panel you see there.

B: Walk through the portal to join your partner.

Proceed through the dual door to the disassembly machines.

Chamber 02: "Buttons"

B: Shoot a blue portal in the panel on this side of the goo moat and a purple one on the other side. Go through and stand next to the door.

O: Press the pedestal button to open the door.

B: Go through the door, then shoot a purple portal in the panel you find in the corridor.

O: Go through the blue portal to join your partner.

Go through the dual door. Each of you portal up to one of the two pedestal buttons on the high platforms. Stand in front of the button, then have one of you start a countdown. Simultaneously press each of your buttons, then quickly drop down, go to the lower pedestal button on your side of the room and press it. If all four buttons are pressed in time, a ball will be released. One of you pick up the ball and place it into the receptacle to unlock the exit door. Proceed to the disassembly machines.

Chamber 03: "Lasers"

B: Note the two laser relays, one of which is in a small alcove. Pick up the pivot cube and place it in the laser, aiming the beam at the side of the alcove. Shoot a portal at the panel where the laser strikes, then shoot the other on one of the side walls inside the alcove so that it passes through the laser relay and hits the other wall.

O: Place a portal where the laser strikes inside the alcove, then put your other portal on the outside wall of the alcove facing the other relay. This should activate it and open the door.

Pass through the dual door and into the next chamber.

B: Take the pivot cube, then hold it in the laser beam.

O: Stand on the button to reveal the turrets behind the glass.

B: Aim the laser through the glass to destroy the turrets. Then aim the laser so that it strikes the left panel of the two that you can see that are side-by-side.

O: Walk into the glass corridor and shoot a portal at the panel on the wall on your right. Turn around and shoot your other portal at the panel there. Then go stand under the laser receiver.

B: Walk to the panel the laser is striking. Shoot a portal into each of the two side-by-side panels. This will activate the laser relay and receiver and create stairs to the dual door. Head for the disassembly machines.

Chamber 04: "Rat Maze"

UNLOCKABLE: Rock/Paper/Scissors Gesture
Upon arrival in this chamber, you will automatically perform the paper/rock/scissors gesture. It will then be unlocked for both players in the gesture menu.
END UNLOCKABLE

Walk past the laser and the exit on your right and continue around the corner. You will see a maze-like area behind a glass pane. Nearby are two buttons, one labeled with an up arrow and one labeled with a down arrow.

B: Put a blue portal on the nearby panel, then shoot your purple panel into the start position in the maze. Go through your blue portal, then walk until you are blocked.

O: Stand on the button which moves the blocks down.

B: Walk forward and drop down off the edge, then move forward some more so that you're not standing on the movable block.

O: Stand on the other button to move the blocks up.

B: Drop down into the hole revealed by the block. Shoot a purple portal in the panel on the floor here, but don't go in. Walk to the edge at the other end of the corridor.

O: Go back to the first button.

B: Stand on the block which has lowered down in front of you.

O: Step off the button.

B: Grab the pivot cube, then stand on the movable block again.

O: Stand on the same button again, moving the blocks down.

B: Move forward to the next block.

O: Step off the button.

B: Bring the cube back through the purple portal. Take it back to the laser and place it so that it redirects the beam into the adjacent panel. Shoot a portal there and the other at the panel above and behind you to activate the laser relay over the exit.

Proceed through the exit to the disassembly machines.

Chamber 05: "Laser Crusher"

B: Take the pivot cube and hold it in the laser beam. Aim it at the receiver on the left, which raises the left crusher.

O: Walk under the raised crusher and onto the platform over the goo.

B: Aim the laser beam into the middle receiver, between the two crushers.

O: Quickly portal over to the lift which is rising out of the goo near the other crusher.

B: Allow the lift to rise a little ways above the crusher, then aim the laser beam at the receiver on the right, raising the right crusher.

O: Jump under the crusher and continue to the exit. Move the portal that is by the second crusher to the panel you find here.

B: Aim the laser at the first (left) receiver again. Leave the pivot cube here and walk under the crusher and through the portal to join your partner.

Go through the dual door and into the disassembly machines.

The Scanner: "Behind the Scenes"

B: Walk along the catwalk until you encounter a panel on your right. Use it to portal into the office area across the gap. Walk through the office until you encounter two switches.

O: Follow your partner to the switches.

Use the countdown function of your ping tool to help you pull both switches at once.

B: Quickly shoot a portal through the door before it closes. Shoot the other one into the wall and go through. Find the disc, then take it back to the player and put it in.

ACHIEVEMENT: Team Building
This achievement is awarded for completing all test chambers in Course 01. If you've been doing the chambers in order, you'll get the achievement now.
END ACHIEVEMENT

Course 02: Mass & Velocity

In The Hub, use the panel on the floor to portal over to the door for Course 02, marked "Team Building." Go through and check the chamber selector to make sure it's set to send you into the first chamber, then proceed to the disassembly machines.

Chamber 01: "Flings"

B: Portal up to the higher ledge.

O: Put a portal on the panel facing the lower ledge, then go through your partner's portal to join them. Put your other portal on the panel on the floor directly below the ledge you're on.

Jump into the portal on the floor one after the other to be flung across the room onto the lower ledge. Head through the fizzler and the dual door.

B: Portal up to the platform across from the higher ledge.

O: Put a portal on the panel across from the higher ledge, and the other on the panel on the floor directly below the platform your partner is on.

B: Jump into the portal your partner made on the floor to be flung across the room onto the upper ledge.

O: Portal up to the same platform that your partner first went to. Put one portal on the floor and the other on the panel on the wall below and to the left of the ledge where your partner is. Jump into the portal on the floor to fling yourself to the lower ledge.

Step on your buttons to release a ball. Have one of you put it into the receptacle, then head through the exit and into the disassembly machines.

Chamber 02: "Infinifling"

B: Walk past the pedestal button and step into the alcove with the fizzler in it.

O: Put an orange portal above your partner and a red one below him to send him into an infinite fall. Press the pedestal button to move the wall out of the way, then quickly turn to the left and fire an orange portal at the angled panel to fling your partner across the goo to the other side. Once he's across, go stand in the alcove.

Repeat the procedure with reversed roles to bring Orange across, using the pedestal button on the far side of the goo to move the wall. Go through the dual door and into the disassembly machines.

Chamber 03: "Team Retrieval"

B: Stand in the alcove on the right side of the fizzler.

O: Put an orange portal above your partner and a red one below him to send him into an infinite fall. Walk around to the other side of the fizzler (not through it) and shoot an orange portal onto the panel high up on the wall to fling your partner across to goo to the other side. Then stand on the button to raise the platforms over the goo.

B: Press the pedestal button to dispense a ball. Pick it up and join your partner on the other side. Walk up to the ledge and hold the ball up as high as you can.

O: Walk up the steps, through the fizzler, then around to where the ball is. Take it from your partner.

B: Walk up the steps and through the fizzler, then portal up to the higher ledge.

O: Walk through your partner's portals and put the ball in the receptacle.

Walk through the opened exit and into the disassembly machines.

Chamber 04: "Vertical Flings"

B: Stand in the alcove to the right of the two vertical shafts.

O: Put an orange portal above your partner and a red one below him to send him into an infinite fall. Put an orange portal onto the bottom of one of the two shafts, then quickly put the red one onto the bottom of the other one.

B: As you fly up each shaft, press the pedestal button. If you miss, just keep trying, as you can oscillate between the two shafts as long as you need to get them both.

When both buttons have been pressed in close succession, four balls will be dispensed. One of you grab a ball and place it on the receptacle to open the exit door.

ACHIEVEMENT: Four Ring Circus
Note: This is the easiest way I've found to get this achievement, but it requires a quick movement from your partner that may be more difficult using a controller; therefore it is recommended that your partner be on PC or Mac, where they can use a mouse. We'll assume that the one who needs the achievement is Blue; reverse roles if Orange needs it.

B: Shoot a portal at the bottom of one shaft. Stand in the other one, then jump straight up and shoot the other portal under yourself while in mid-air. You will ocillate between the two portals.

O: Shoot one of your portals on an open section of floor. Allow your partner to complete at least one full oscillation so that he has gone INTO both of his portals. Then as soon as he passes through a portal, quickly replace it with your other portal, so that he never touches the ground. After he performs one more complete oscillation, he will earn the achievement.
END ACHIEVEMENT

Chamber 05: "Catapults"

B: Put one portal on the angled panel, and the other above the faith plate.

O: Step on the faith plate to get launched through the fizzler.

B: Follow your partner onto the faith plate.

Head through the dual door.

B: Walk through the fizzler, then look up to see a panel up in the air. Put a blue portal on the side facing the fizzler, and a purple one on the other side.

O: Put an orange portal above the faith plate, and a red one on the angled panel. Step on the faith plate to be launched over the fizzler, through the upper panel, and land on the lower platform. Put a red portal on the angled panel.

B: Walk through the fizzler and step on the faith plate to get launched to the dual door.

O: Drop through the red portal on the angled panel to drop onto the faith plate and get launched over to your partner at the dual door.

B: Walk through the dual door, then shoot a blue portal above the faith plate on your right. Place a purple portal on the panel on the floor below the platform where the cube is sitting. Step on the faith plate and grab the cube in mid-air. Put down the cube and move the purple portal onto the angled panel across from the fizzler. Pick the cube back up, walk over to the ledge next to the fizzler, and hold up the cube as high as you can.

O: Step on the faith plate to get launched through the fizzler. Walk over to the edge and take the cube from your partner. Put the cube on the button to open panels in the wall, revealing an alcove containing a fizzler and two panels.

B: Move the purple portal to the panel on the wall across from the newly-revealed alcove. Step on the faith plate to launch yourself into the alcove. Put a portal on each of the panels behind the fizzler. Wait there without touching the fizzler.

O: Put a portal on the panel on the wall across from the alcove, put the other one above the faith plate, then step on the faith plate. You'll be launched through the fizzler, through your partner's portals, back through the fizzler, and up onto the platform where the dual door is found. Shoot a portal on the panel on the ground below, then shoot the other one on the panel to the right of the dual door.

B: Drop into the panel your partner made on the floor to join her.

UNLOCKABLE: Dance Gesture
Upon both partners reaching the dual door, you will automatically perform the dance gesture. It will then be unlocked for both players in the gesture menu.
END UNLOCKABLE

Head through the dual door and into the disassembly machines.

Chamber 06: "Multifling"

B: Walk through the fizzler into the far half of the chamber. Turn right and put a portal on each of the two angled panels you see there.

O: Portal up to the faith plate on the right. Shoot a portal into each of the angled panels across the chamber, then step on the faith plate. You'll fly through your portals, through your partner's portals, and onto the platform at the exit. Press the pedestal button to drop a cube onto the faith plate, which will then get lobbed through the portals and up to your position. Staying on the platform, take the cube and drop it off the edge so that it lands down below. Then replace your partner's portals with your own.

B: Take the cube and place it on the receptacle. Go back through the fizzler and portal up to the faith plate. Shoot a portal into each of the angled panels on the far side of the chamber, then step on the faith plate to join your partner.

Head through the dual door into the next room.

B: Step onto the faith plate to land on the opposite platform. Shoot a portal on the platform held above the platform where your partner stands. Shoot the other one on the angled panel to the left. Step on the faith plate.

O: About one second after you partner steps on the faith plate, press the pedestal button to dispense a cube.

B: When you fly out of the portal on the angled panel, you'll see the cube flying towards you in the opposite direction. Snag it and hold onto it until you land on the platform where your partner stands. Step on the faith plate to go back to the other platform. Drop the cube on the receptacle to open the exit.

ACHIEVEMENT: Iron Grip
If you accomplish this on the first attempt (i.e. you don't lose a cube in the goo), you'll both be granted this achievement.
END ACHIEVEMENT

O: Step on the faith plate to join your partner and head through the exit with him.

Chamber 07: "Fling Crushers"

Each of you pick a faith plate and a button. Place one portal on the bull's-eye across from your faith plate, and the other on the wall opposite your button, on the panel that has been divided into small squares. Use the timer on the ping tool to step on the faith plates simultaneously and open the door. Go through.

B: Stand on the lift located at ground level in the corner. Shoot one portal on the floor directly in front of you. Shoot the other on the panel across from the faith plate on the wall. (It's just to the right of the pneumatic tube.)

O: Look down the hallway to see a laser beam striking the ground. Turn around and shoot a portal on the wall at ground level, directly across from that hallway. Turn to the left and shoot your other portal at the checkered panel on the wall, across from the laser receiver. Take the pivot cube and go down the hallway towards the laser. This will trigger a sequence of crushers. Hold the pivot cube in the beam and aim it through your portal so that it strikes the laser receiver. This will raise the lift on which your partner stands. Do not put the cube down; continue aiming the beam steadily at the receiver.

B: When the lift stops, jump into the portal on the floor to be flung into the faith plate and down the hallway into a button which deactivates the crushers. Enter the next room and stand next to the door.

O: Bring the cube with you into the next room. Stand to the side of the faith plate that's closer to the door and drop the cube on the faith plate. Immediately run for the door.

When the cube hits the button, the door will open. Hurry through, because it will close again quickly. Head through the dual door and into the disassembly machines.

The Blueprints: "Industrial Fan"

B: Facing the giant fan, turn to the left to see two angled panels labeled 01 and 02. Shoot a blue portal at the 01 panel. Now turn right and walk to the edge of the platform, to the right of the laser. Look down to see a concrete section of floor; shoot a purple portal there, leaving room next to it for another one for your partner.

O: Shoot an orange portal on the angled panel labeled 02. Turn around, stand next to your partner and look down. Shoot a red portal on the ground next to your partner's portal.

B: Jump into the purple portal to be flung into the button.

O: After your partner hits the button, a chirping sound will be heard. On the third chirp, drop into your portal. Catch the pivot cube as you fly over the dispenser tube. Portal back to your partner with the pivot cube. Note the two rectangles marked in yellow on the floor. Facing the fan, stand behind the one on the left. Hold the pivot cube in the laser beam so that it is redirected into the booth in front of you and strikes the receiver. This stops the fan. Do not put the cube down; just stay there and hold it steady until you partner is past the fan.

B: Behind your partner is another slanted panel; move the blue portal there. Jump into your purple portal to be flung across the room and to the fan. Go through the fizzler behind the fan. As you enter, turn to your right to see another laser receiver. Put a portal on the opposite wall, then continue forward. In the next room, put the other portal on the wall, under and a little to the left of the clock.

O: Bring the cube to the other rectangle, pointing it in the same direction so that the laser beam strikes a panel. Put it down there. Put one portal on that panel, then put the other one on the flat panel behind you labeled 01, next to the pneumatic tube.

B: Adjust your portals as needed in order to cause the laser beam to strike the receiver. This stops the fan permanently.

O: Put a portal on the slanted panel facing the fan, and the other on the ground below the edge of the platform. Jump in to lob yourself to the fan. Go through the fizzler and join your partner.

Stand at the switches on each side of the door, and use the timer on the ping tool to help you pull them simultaneously. Proceed into the office area. Find the disc, and have one of you put it in the player.

ACHIEVEMENT: Confidence Building
This achievement is awarded for completing all test chambers in Course 02. If you've been doing the chambers in order, you'll get the achievement now.
END ACHIEVEMENT

Course 03: Hard Light Surfaces

Back at The Hub, you'll see the entrance to Course 03 high above the one for Course 02. There will be an angled panel up there; portal up to it to land on the faith plate and be flung up to the Course 03 door. Check the chamber selector to ensure that the first course is selected, and proceed to the disassembly machines.

Chamber 01: "Cooperative Bridges"

B: Shoot a blue portal at the point on the wall where the hard light bridge strikes. Shoot the purple one on the wall to the left of that to extend the bridge across the goo. Walk through your portal across the bridge, then land on the platform on the other side.

O: Follow your partner across the bridge and get off onto the platform.

B: Move the purple portal onto the panel at the left. Hop onto the bridge and follow it to the right.

O: Follow your partner. Shoot an orange portal at the wall where the bridge strikes, then shoot a red one at the panel on the wall to the right of it.

Go through the orange portal, then follow the bridge to the next platform. Hop off and go through the dual door.

B: Shoot a blue portal at the spot high up on the wall where the light bridge strikes.

O: Step on the faith plate.

B: When your partner reaches the fizzler, shoot a purple portal on the wall directly below her. This will extend a bridge under her and catch her.

O: Walk through the purple portal so that you're standing on the bridge between the emitter and the blue portal.

B: Move the purple portal under the blue one so that the bridge passes next to the pedestal button.

O: Walk back through the blue portal and press the pedestal button to release a ball. Then walk back through the purple portal.

B: Move the purple portal high up on the wall so that the bridge passes directly over the faith plate and across the room to the platform where the exit door is. Then go pick up the ball.

O: Walk through the blue portal again and follow the bridge all the way across the room. Drop onto the platform, then look at the spot on the wall where the bridge strikes and shoot an orange portal there.

B: Still holding the ball, step on the faith plate.

O: While your partner is in midair, shoot the red portal directly under your orange one, as far down on the wall as you can, so that you extend a bridge underneath him to catch him.

B: Join your partner on the platform and put the ball in the receptacle to open the exit door.

Chamber 02: "Bridge Swap"

B: Shoot a blue portal where the hard light bridge hits the wall. Shoot the other on the adjacent wall to extend the bridge down the corridor over the goo. Don't stand on the bridge yet.

O: Walk to the end of the bridge and look to the left to see a panel. Shoot an orange portal into that panel. Walk back to the intersection between the two bridges and replace the blue portal with a red one. Jump back up onto the platform above the hard light emitter.

B: Go through the red portal and you'll see another panel a little to the right. Shoot a blue portal there. Go back through the orange portal, then turn and replace the red portal with a purple one. Go through and follow it to the end.

O: Follow your partner along the bridge, and shoot an orange portal at the panel the bridge strikes. Shoot a red portal on the wall to the right, on the second-highest row of panels.

Go through the orange portal and across to the dual door.

Chamber 03: "Fling Block"

ACHIEVEMENT: Portal Conservation Society
If you're not trying to earn this achievement, this chamber can be completed significantly more easily, since you don't have to be stingy with portals. However, this walkthrough will assume you're trying to get it.

B: Walk right up to the edge and look to the left so that you can see a tiny sliver of the panel where the light bridge strikes. Shoot a blue portal there. Then shoot a purple portal at the panel in front of you on the platform you're standing on. Go through and walk to the hard light emitter.

O: Follow your partner and stand to one side of the bridge next to the pedestal button.

B: Stand ON the emitter and edge yourself to the left so that you can see the surface of the extended panels above you. Shoot a purple portal on that surface so that the bridge extends under (or at least close to) the dispenser. Get back on the bridge, walk through the blue portal, and stand at the dispenser.

O: Press the pedestal button, then go through the blue portal and follow your partner.

B: Catch the ball, then follow the bridge to the platform. Jump onto it and put the ball in the receptacle to open the exit door. Wait until your partner is safely on the platform before proceeding.

Go through the fizzler and dual door unto the next chamber.

O: Shoot an orange portal at the panel where the hard light bridge strikes. Carefully walk past faith plate and stand against the wall next to it, at the very edge of the goo. Zoom in on the panels on the ceiling, and shoot a red portal exactly on the boundary between the second and third panels from the right, right in the center of that line.

B: Stand behind the faith plate, then walk directly into it to be bounced off the hard light surface and into the exit alcove. No problem if you die, since you have no active portals; just try again.

O: Once your partner's safely in the exit alcove, follow exactly as he went to join him there. To get the achievement, you have to do it on the first attempt, or start the whole chamber over, since your portals will disappear if you die.
END ACHIEVEMENT

Chamber 04: "Catapult Block"

B: Shoot a blue portal at the point the light bridge strikes the wall.

O: Step on the faith plate.

B: When your partner reaches the apex of her flight, shoot a purple portal directly underneath the blue one so that she lands on a bridge extended under her.

O: Walk through the purple portal. Replace the blue portal with an orange one. This closes the purple portal, removing the lower bridge.

B: Step on the faith plate.

O: When your partner reaches the apex of his flight, shoot through the hard light bridge to replace the purple portal with a red one, restoring the lower bridge under him.

B: Walk through the red portal to join your partner.

O: Look up to see a panel angled down towards you. Move the red portal to extend the bridge down to the platform.

Walk through the orange portal, down the light ramp to the platform, and through the dual door.

B: Shoot a blue portal where the light bridge strikes the wall. Shoot a purple portal through the light bridge onto the wall directly below the blue portal.

Walk through the blue portal and down the bridge. Hop down to the ledge below.

B: Shoot a purple portal at one of the side walls to extend the bridge sideways in front of you, close enough so that you can jump onto it.

O: Put an orange portal on the wall where the bridge strikes, and put a red portal on the wall near the far ledge where the light is.

Hop onto the bridge, walk through the orange portal, then jump onto the next ledge. A lift will rise when you arrive.

B: Stand on the ledge and look away from the exit to see a narrow corridor with no floor. There is a panel on the far wall; move your purple portal there to extend a bridge towards you. Hop onto the bridge and walk along it until you are standing directly over a panel.

O: Above and just to the right of the bridge is a panel; shoot a portal there. Shoot the other portal on the panel directly under your partner.

B: Face the exit, then move the purple portal to the wall to the right of the exit. This will remove the bridge under your feet, dropping you into your partner's portal and flinging you to the dual door.

B: Shoot a portal in the nearby panel, and the other on the wall next to your partner.

O: Walk through the portal your partner made to join him.

Walk through the dual door to the disassembly machines.

Chamber 05: "Bridge Fling"

B: Shoot a blue portal to one side of the floor below the up arrow. Shoot a purple portal above the faith plate. Step on the plate to land on the platform. Shoot a purple portal at the panel there where the light bridge strikes, then drop back down from the ledge.

O: Replace the purple portal above the faith plate with an orange one. Put a red portal on the raised panel on the floor.

B: Step on the faith plate to be launched in the air. While in mid-air, shoot a blue portal at the wall to make a bridge underneath yourself.

O: Move the red portal to the same spot where your partner first shot his blue portal, to one side of the floor below the up arrow. Step on the faith plate to land on the platform. Step onto the light bridge and go through the purple portal.

B: Walk up to your partner at the blue portal and look to the right to see some panels. You are going to shoot a portal at the bottom-left one. Position yourself so that you are in line with that panel, and walk up to the edge of the bridge so that your partner can stand next to you.

O: Stand next to your partner, so that you are standing two across on the bridge.

B: Move the blue portal to the bottom-left panel, removing the bridge you're standing on and creating one underneath which is perpendicular to the previous one.

Proceed down the bridge and hop into the alcove. Go through the dual door.

B: Put one portal on the angled panel facing the lower fizzler. Put the other on the panel above the faith plate. Step on the faith plate to be flung through the lower fizzler onto the platform on the other side. Shoot a blue portal at the panel struck by the hard light bridge. Shoot a purple portal at the panel on the opposite wall next to the platform where your partner stands.

O: Hop onto the bridge and pass through the purple portal. Turn right and shoot a portal on the angled panel next to your partner. Go back through your partner's portal and onto the platform you started at. Shoot your other portal above the faith plate and step onto it. This will fling you through the upper fizzler and onto the platform beyond it.

B: Move the purple portal to the panel on the wall next to the platform where your partner stands, moving the bridge over there.

O: Shoot an orange portal on the angled panel on this platform, then hop down onto the bridge your partner created for you. Walk through the purple portal.

B: Move the purple portal back to the panel it was on previously, moving the bridge near the entrance platform.

O: Go back through your partner's portal and hop onto the platform. Shoot a red portal above the faith plate and step onto it. You'll be flung the other direction through the upper fizzler to the exit platform. You will now reverse roles to get your partner across. Replace the blue portal with an orange one, then shoot your red portal to place a bridge across the room that your partner can jump onto.

B: Hop onto the bridge made by your partner and go through the red portal. Turn right and shoot a portal on the angled panel you see there. Go back through your partner's portal and onto the platform you started at. Shoot your other portal above the faith plate and step onto it.This will fling you through the upper fizzler and onto the platform beyond it.

O: Move the red portal to the panel on the wall near your side of the room, moving the bridge there.

B: Shoot a blue portal on the angled panel on this platform, then hop down onto the bridge your partner created for you. Walk through the red portal.

O: Move the red portal back to the panel it was on previously, moving the bridge near the entrance platform.

O: Go back through your partner's portal and hop onto the platform. Shoot a purple portal above the faith plate and step onto it. You'll be flung the other direction through the upper fizzler to the exit platform to join your partner.

Go through the dual door to the disassembly machines.

Chamber 06: "Turret Walls"

B: Shoot a blue portal at the point on the wall where the hard light surface strikes. Turn to face the entrance and shoot a purple portal on the panel to the left of it, extending it across the room and blocking the turrets.

O: Shoot a portal on the unblocked wall near you. Shoot the other to the left of the stairs.

Go through the orange portal.

ACHIEVEMENT: Can't Touch This (chance #1)
Stand where you would get shot if the hard light shield weren't in the way, then perform the dance gesture to earn this achievement. Each player earns it separately.
END ACHIEVEMENT

Proceed quickly up the stairs. (The turrets have clear line of sight to shoot you at the upper part of the stairs.)

B: Shoot a purple portal on the panel to the right of the next set of stairs. This blocks the turrets on the right, but the ones on the left remain unblocked.

O: Shoot an orange portal on the panel to the left of the purple one. Proceed down the corridor just far enough to see the point where the hard light surface strikes the wall and shoot a red portal there. This will block the remaining turrets.

ACHIEVEMENT: Can't Touch This (chance #2)
Stand where you would get shot if the hard light shield weren't in the way, then perform the dance gesture to earn this achievement. Each player earns it separately.
END ACHIEVEMENT

Go quickly up the next set of stairs and through the dual door.

B: Shoot a blue portal where the hard light bridge strikes the wall. Shoot a purple one directly above it to extend the bridge next to a small alcove.

Go through the blue portal. Walk along the bridge and quickly duck into the small alcove to avoid turret fire.

O: Higher up you can see another hard light surface, this one oriented vertically to form a shield rather than a bridge. Shoot an orange portal where it strikes the wall. Turn to face the back wall of the alcove and shoot a red portal on the rightmost panel, extending a shield across the room.

B: Move the purple portal next to the red portal to form a bridge behind the shield. Walk along the bridge and stand facing the pedestal button on the other side of the shield.

ACHIEVEMENT: Can't Touch This (chance #3)
Stand where you would get shot if the hard light shield weren't in the way, then perform the dance gesture to earn this achievement. Each player earns it separately.
END ACHIEVEMENT

O: Move the red portal to the panel to the left of the purple portal, moving the shield behind your partner.

B: Quickly move forward, press the button, and step back onto the bridge again.

O: As soon as your parter's back on the bridge, move the red portal back to its previous position to restore the shield.

B: Grab the ball before it rolls into the goo. Walk down the bridge and put it in the receptacle.

O: Go join your partner, then move the red portal to the other side of the bridge again to clear the way to the exit.

Move quickly through the exit and to the disassembly machines.

Chamber 07: "Turret Assassin"

B: Staying behind the glass, shoot a blue portal at the wall where the hard light surface strikes. Shoot the purple portal at the bottom-right panel of the wall in front of you. This will shield your partner from the turret.

ACHIEVEMENT: Can't Touch This (chance #4)
Stand where you would get shot if the hard light shield weren't in the way, then perform the dance gesture to earn this achievement. Each player earns it separately.
END ACHIEVEMENT

O: Shoot an orange portal at ground level at the wall next the purple portal. Shoot a red portal on the wall of the alcove to the left. Walk through without stepping on the faith plate.

B: Making sure you're standing behind the glass, quickly move your purple portal one panel up to shield your partner. The turret will busy itself shooting at you, but the glass blocks the bullets.

O: Put an orange portal on the ceiling above the faith plate. Put a red one on the angled panel to the right of the turret. Step on the plate to fling yourself into the turret and onto the opposite platform.

B: Leaving your partner's portals in place, portal up to the faith plate and step on it to join your partner.

Pass through the fizzler and the dual door to enter the next part of the chamber.

B: Peek around the edge of the glass and shoot a blue portal where the hard light surface strikes the panel, then quickly duck behind the glass again. Shoot a purple on the column of panels furthest to the left, low enough to shield the button from the turrets. Then go over and stand on the button to lower a panel in the ceiling. Stay on that button.

O: Shoot a portal on the newly-revealed panel. Shoot the other on the wall nearby. Go through quickly, as one of the turrets can see you at that angle. Shoot an orange portal at the panel with the bull's-eye on it. Shoot a red portal slightly lower on the column of panels to the left of the bull's-eye panel. Press the pedestal button to lob two balls and a cube through the portals and into the turret on the nearby column, and possibly the far turret as well. If you don't get them both, adjust the red portal as needed until they've both been taken out. Repeat the procedure on the next column of panels to left to take out the other two turrets. Move the red portal to the overhead panel, the one being held in place by your partner standing on the button. Press the pedestal button again to toss two balls and a cube to your partner.

B: Step off the button and grab the cube. Put it on the button to keep that
overhead panel in place without you having to stand on the button yourself. Now
use that overhead panel to portal over to the other side and join your partner.

Go through the fizzler and the dual door to the disassembly machines.

The Security Code: "Bridge Testing"

Walk along the catwalk until you enter a room with a fizzler on the left and a laser in a small alcove on the right.

B: Walk through the fizzler and grab the ball as it shoots out of the horizontal dispenser. Without touching the fizzler, take it to the opposite wall; you'll see a panel there. Hold the ball up to the panel.

O: Shoot a portal through the grating above the fizzler on to the panel on the wall where your partner is holding the ball. Shoot your other portal on the wall on this side. Peek through the portal without going all the way through and take the ball from your partner. You may need to crouch to get it. Stick it into the alcove to interrupt the laser and open the door.

Go through the newly-opened door and proceed to the next area.

B: Take the catwalk that goes through the fizzler, but turn left just before you go through it. You'll see hard light emitters moving along a vertical conveyor belt. Press the button to stop the conveyor belt, leaving a hard light bridge hitting a panel. Shoot a blue portal at this panel. Now look up to see two parallel overhead beams. As you watch, a ball will periodically be dispensed and sail through the air directly underneath one of these beams. There is a panel on this beam; shoot a purple portal there to extend the hard light surface downward from it. The balls will now bounce off the hard light surface. Stay on this side of the fizzler without touching it.

O: Pass through the fizzler and watch a ball bounce off the bridge, then bounce off an angled panel. Shoot a portal at this panel. Now look up to see the two parallel beams. One has your partner's portal on it with a hard light bridge coming out of it. Look at the other one and you'll see another panel on it. Shoot your other portal there. The ball will now drop out of that portal after bouncing off the hard light surface.

B: Near the button you pressed is another angled panel. As soon as a ball bounces off the hard light surface, move the purple portal to that panel. This will catch the ball as it drops out of your partner's portal and cause it to roll down the light ramp. Let it roll through the purple portal and nab it from the bridge next to the button. Being careful not to touch the fizzler, carry the ball to the door opposite the entrance, where you'll see another small laser alcove. Put the ball in it to interrupt the laser and open the door.

In the office on the other side of the door, you'll find a pair of switches on either side of another door. Use the timer on the ping tool to coordinate your actions so that you throw both switches simultaneously to open the door. Proceed into the next area.

B: There's a hard light bridge on the left as you enter. Shoot a portal on the panel it strikes. Look up and to the right to see another panel on a vertical beam; shoot the other portal there to extend the bridge across the area. Go through your blue portal and walk until you are standing directly above a panel with the number 1 on it.

O: Follow your partner through the blue portal, but stop when you are standing directly above a panel with the number 2 on it. Shoot a portal directly through the hard light bridge onto the #2 panel. Look at the purple portal, then down and to the right to see an angled portal with a matching 2 on it. Shoot your other portal there.

B: Opposite the angled portal where your partner just shot a portal is another one with the number 1 on it. Shoot a portal there (which will cut off the bridge), then quickly look straight down and shoot the other portal at the panel you're falling towards. You and your partner will be flung over the platform where the exit is, colliding in mid-air and landing on the platform.

UNLOCKABLE: Hug Gesture
Upon landing on the platform, you will automatically perform this gesture. It will then be unlocked in your gesture menu.
END UNLOCKABLE

Go through the door to enter an office area, where you'll see a disc player. On one of the desks you'll find the disc; have one of you grab it and put it in the player. GLaDOS tries to prevent you from hearing the security code: 5 33 41 18. It doesn't matter though; you don't need it.

ACHIEVEMENT: Bridge Building
This achievement is awarded for completing all test chambers in Course 03. If you've been doing the chambers in order, you'll get the achievement now.
END ACHIEVEMENT

Course 04: Excursion Funnels

Having returned to The Hub, you'll see a hard light bridge extending down the entrance to Course 04. After checking the chamber selector to ensure that the first course is selected, proceed to the disassembly machines.

Chamber 01: "Cooperative Funnels"

B: Put a blue portal on the panel struck by the excursion funnel. Go up to the edge, where you can see the spinning blades below. Turn right and put a purple portal on the panel on the wall.

O: Jump into the funnel.

B: Jump into the funnel behind your partner.

O: Shoot an orange portal at the end of the funnel, and shoot the red portal at the higher panel on your left, extending the funnel across and to the right. Ride the funnel through the portal and to the end, where you are pressed against a button which raises a platform below. Stay there.

B: When you are above the platform raised by your partner, move out of the funnel to land on it. Go through the door, then turn around and move the purple portal to the panel you see there. The funnel will bring your partner to the dual door, which will then open.

Chamber 02: "Funnel Drill"

B: Step on the button to create an opening in the wall to the right. Then turn back to the left and shoot a blue portal at the panel in the middle of the goo where the excursion funnel ends. Shoot a purple portal at the wall on the left so that the funnel is extended through the fizzler. Stay on the button.

O: Step on the faith plate to land in the funnel and be carried through the fizzler and onto a platform. Press the pedestal button to release a ball. Pick it up.

B: Look through the area opened by the button you're standing on and move the purple portal to the panels you can see through that opening to move the funnel over there. Step off the button and walk over to the exit.

O: Stick the ball into the funnel, then hop down and walk through the fizzler. Shoot at the spot the funnel is striking on the panel. Walk to the other side of the panel and shoot your other portal in the middle of that panel there.

When the ball interrupts the laser, the exit will be unlocked. Go through it and into the disassembly machines.

Chamber 03: "Funnel Catch"

B: As you enter the next chamber, walk over to the depression on the right to see a panel on the floor. Shoot a blue portal there, then shoot a purple portal on the panel struck by the excursion funnel. Hop into the funnel and let it raise you to the ceiling. Aim your portal gun at the angled panel to the right of the excursion funnel, but don't fire yet.

O: Stand on the button to lower a barrier on the ceiling. Shoot an orange at the panel on the wall across from the exit, then train your crosshairs at the panel above the funnel emitter, where the purple portal is. Stay on the button.

B: Shoot a purple portal at the angled panel. This will cut off the funnel and cause you to fall into your blue portal.

O: As soon as the purple portal disappears from the panel above the funnel, shoot a red one to replace it. This will cause the funnel to be extended across the room to the exit.

B: You are flung into the barrier that your partner is holding in place for you and land in the funnel. Ride it to the exit platform and step off to the left. Grab the cube and, staying on the platform, hold it over the edge and drop it. Replace the orange portal with a blue one, then train your crosshairs on the panel above the funnel emitter.

O: Step off the button and go get the cube your partner dropped. Bring it back and put it on the button. Shoot an orange portal on the panel above the funnel emitter, and shoot a red one on the floor panel. Hop into the emitter and ride it to the ceiling. Then aim at the angled panel on the wall and move the orange portal there.

B: As soon as the orange portal disappears from the panel above the funnel, shoot a purple one to replace it.

Orange will land in the funnel and be brought to the exit. Go through it and into the disassembly machines.

Chamber 04: "Funnel Laser"

B: Step onto the faith plate to be shot over to the opposite platform. Look over the edge and shoot a blue portal at the spot where the excursion funnel ends. Turn around and shoot a purple one on the wall at ceiling level, so that the funnel ends above the doorway to the room above. Drop off the edge into the funnel and ride it to the end. Move out of it and into the room.

O: Zoom in on the blue portal and replace it with an orange one. Turn around and look at the high panel behind you. Shoot a red portal at the panel down and to the left of that one, so that the funnel is extended under the dispenser.

B: Press the pedestal button to drop a pivot cube into the funnel, then drop down to the level below, taking care not to step on the faith plate. Snag the pivot cube out of the funnel. Put it down and shoot a blue portal at the spot on the wall where the funnel ends. Put the other portal on the wall to the left so that it takes you back to the upper room. Take the pivot cube and hop into the funnel. Ride it to the upper room and go in.

O: Move the red portal to the wall below the glass of the upper room on the other side of the chamber. This will extend a funnel to the area near the exit. Step onto the faith plate to be flung to the other side, then drop into the funnel and ride it to the end.

B: Put the pivot cube in the laser beam so that it aims at the panel wall. Shoot a blue portal at the wall. Leave the upper room and drop to the level below. Drop into the funnel and ride it to join your partner. Shoot a purple portal at the panel opposite the laser receiver so that the laser activates it, which will create stairs up to the exit.

UNLOCKABLE: Trick Fire Gesture
When you reach the camera at the end of this chamber, you will automatically perform this gesture. It will then be unlocked in your gesture menu.
END UNLOCKABLE

Chamber 05: "Cooperative Polarity"

B: Shoot a blue portal where the excursion funnel ends. Shoot an orange portal at the wall to the right of the exit tunnel.

O: Step on the faith plate to enter the funnel and ride it to the upper alcove. Pick up the cube.

B: Step on the button to reverse the direction of the funnel.

O: Take the cube with you into the funnel and ride it back to your partner.

B: Move the orange portal to the panel opposite the wall-mounted receptacle above the exit tunnel.

O: Drop the cube on the faith plate to launch it into the funnel.

Wait near the exit for the cube to enter the receptacle, which raises platforms to allow you to access the dual door.

Chamber 06: "Funnel Hop"

B: Shoot a blue portal at the panel on the ceiling where the funnel ends. Shoot a purple portal at the panel behind the fizzler. This will create a funnel that passes through the fizzler.

O: Hop into the funnel. As soon as you pass through the fizzler, shoot an orange portal at the panel where the funnel ends. Note the crushers there; riding the funnel to that point will kill you. Look to the right and you'll see another panel. Shoot a red portal there. When you get close to the vertical part of the funnel, move into it and ride it to the exit platform. Step on the button to reverse the funnel direction.

B: Hop into the funnel. When you go through the portal, look for the panel opposite the exit platform, the one with the red portal on it. Move your purple portal there.

O: Step off the button to reverse the funnel direction again.

When Blue arrives at the exit platform, head through the dual door to the disassembly machines.

Chamber 07: "Advanced Polarity"

B: Go through the fizzler on the right. Shoot a portal where the funnel ends, then look across the goo to see a vertical panel. Shoot your other portal there. Stand on the button to reverse the funnel.

O: Step on the faith plate to fling over to the other side, then look back the way you came and shoot a portal onto the other vertical panel where the funnel ends. To the right of that there is a panel on the floor; shoot your other portal there. Step on the faith plate to land in the funnel and go through the portal. Coming out the other side, look in the direction of travel and you'll see platform on the right with a button on it. Step onto that platform and stand on the button. This exposes a portal surface at the far end of the chamber.

B: Go back through the fizzler and shoot a portal at the newly-exposed bull's-eye. Replace your partner's portal on the floor, then step on the faith plate. You'll be launched through the portal and upward through a fizzler, and a platform will appear under your feet. Go to the other side of the platform you're on and look down to see the funnel emitter. Shoot a blue portal where the funnel ends, then shoot a purple one at the vertical panel facing you.

O: Step off the switch and hop into the funnel. Step out of the funnel at the platform under the horizontal fizzler. Stand on the panel here.

B: Move the purple portal under your partner's feet to carry them up to where you are.

Go through the dual door and into the disassembly machines.

Chamber 08: "Funnel Maze"

B: Look down over the edge to see the excursion funnel, and shoot a blue portal on the panel where it ends. Shoot a purple portal on the panel to the left of the first one so that the funnel is extended through the fizzler. Then go stand next to the button.

O: Hop into the funnel and ride it through the fizzler. Stand on the panel here. Shoot an orange portal at the panel where the funnel ends, then shoot a red one under your feet. As you go up, you'll see a spike plate at one side. Face the other way, and when you come up over the top you'll see a panel. Move the red portal to that panel.

B: Quickly step onto the button, reversing the funnel so that your partner moves to the right.

O: As you near the red portal, look upwards to see another panel. Move the red portal there.

B: Step off the button, reversing the funnel again so that your partner moves down.

O: Look down to see the next panel between to spike plates. When you come in line with it, move the red portal there. This causes the funnel to pass under a crusher.

B: Use the button to move your partner back and forth as needed to avoid the crusher. The safest way is to keep her near it but not under it until it goes down, then step off the button to press her against its side. When it goes back up, she'll pass under it safely.

O: When you're past the crusher, look down and shoot a red portal at the panel on the floor. The funnel now passes upwards through the path of another crusher on the wall; face it.

B: Reverse the portal as needed to keep your partner clear of the crusher, then when it deploys, step off the button to press her against its underside.

O: When you clear the smasher, you'll see a tunnel with four arrows pointing at it, with a panel at the end. Move the red portal there.

B: Quickly step off the button to reverse the funnel again.

O: When you reach the platform, move out of the funnel to land on it. (The fizzler will disappear at this point.) Beware of the turret below. Move the red portal to the panel in the ceiling, then jump down, pluck the turret out of the funnel and toss it aside. Take the cube and hop into the funnel.

B: Step onto the button to reverse the funnel again.

O: Ride the funnel through the portal, then hop down to the floor, bringing the cube with you. Nearb you'll see a panel on the floor; go stand on it.

B: Move the purple portal under your partner's feet. Let her ride it up to the ceiling, then move the blue portal onto the angled panel behind the funnel. This will drop your partner and the cube into the purple portal and fling them over to the exit.

O: Drop the cube into the receptacle to create stairs to the exit.

B: Move the blue portal back to where the funnel ends, then hop into the funnel yourself. Ride it to the top, then move the blue portal back to the angled panel to fling yourself over to join your partner.

Proceed up the stairs, through the exit and into the disassembly machines.

The Power-up: "Turret Warehouse"

B: Shoot a blue portal at the spot where the hard light surface strikes the wall. Shoot a purple portal at the bottom panel on the other column of panels to extend a shield in front of the turrets. Go forward and around the corner.

ACHIEVEMENT: Can't Touch This (chance #4)
Stand where you would get shot if the hard light shield weren't in the way, then perform the dance gesture to earn this achievement. Each player earns it separately.
END ACHIEVEMENT

O: Shoot an orange portal at the panel where the excursion funnel ends. Go around the corner and shoot a red portal at the panel on the wall.

Jump into the funnel close together, with Blue in front.

B: Look down and to the right to see a turret assembly line. To the left of the line you'll see a panel on a column. Behind that is another panel. Shoot a purple portal at that panel to extend a shield in front of the assembly line.

O: As you near the end of the funnel, look to the left and you'll see a small balcony with a door in a concrete wall. As soon as you're both in line with it, shoot a red portal into that wall so that you and your partner drop into the redirected funnel underneath you. Be careful to time it so that it catches both of you.

Ride the funnel through the fizzler and pass through the dual door.

B: Shoot a blue portal at the spot where the hard light surface strikes the wall. Look up and to the left and shoot the purple portal at the panel there to block the turrets.

O: Look up to the top of the excursion funnel and shoot an orange portal there. Shoot a red portal at the checkered panel on the floor.

Jump into the funnel, Blue first, then Orange immediately after so that you're close together.

B: As you rise into the next area, you'll see an alcove on the right. Quickly shoot a purple portal there so the shield is redirected to block the turrets at your right.

When you reach the top, you'll see some metal plates on top of some crates. Step out of the funnel and onto those plates.

B: Look between the two funnels at the unblocked turret. Shoot a purple portal at the panel next to it to block it.

O: Turn around and look past the funnel you just stepped out of. You'll see some lights mounted on the wall. On that wall just past the lights you'll see a panel. Move the red portal there.

Go to the other end of the ledge you're on and jump into the funnel. For this one, it's not important to be close together. When you arrive at the next platform, step out of the funnel to the left and go up the stairs.

O: Shoot a red portal on the wall so that the funnel passes down the corridor.

Hop in the funnel and ride it down the corridor. You don't have to be close together on this one, either. Near the end, step out onto the balcony on the left and go through the dual doors.

B: Walk forward and look through the holes in the left wall. Look down to see the hard light surface, and shoot a blue portal at the panel there. Turn around and go to the edge of the platform and you'll see some turrets on your left. Shoot a purple portal into the panel there to block them.

O: Note the panel on the left wall, then follow your companion and shoot an orange portal at the panel where the excursion funnel ends. Then shoot a red portal on the panel you noted earlier to create a funnel going out over the spikes.

Hop into the funnel close together, with Blue in front.

B: Look down to see another turret assembly line, coming from an opening to your left. To the left of the opening is a strip of panels. Shoot a purple portal at the far end of that strip so that a hard light surface crosses in front of the opening, toppling each turret that comes out.

O: At the end of the funnel, wait until the untoppled turrets are cleared from the line. Look down and to the right to see a small room with a panel in it. Shoot a red portal at that panel so that you both drop into the redirected funnel and move the other direction.

ACHIEVEMENT: Party of Three
O: As you ride the funnel, you'll see an office coming up on your right. Just before that is a dark passageway leading off to the right. When you are in front of that passageway, turn to the left and shoot a red portal on the strip of panels there, such that the redirected funnel will take you both down that passageway. You must be very close together or one of you won't make it. Ride the funnel down the passageway and look to your left. A wall will open, revealing a Companion Cube.

Only players who live to see the cube will earn the achievement. If you die, you respawn back at the dual door. Orange's death kills both players, since it fizzles the funnel portals. Blue's death leaves the funnel intact, allowing Orange to still get the achievement. In any case, after passing the cube the funnel takes you to a spike plate, meaning death is inevitable, but that won't erase the achievement. Once you're done with the achievement, simply repeat the process to get back to where you were at before.
END ACHIEVEMENT

Ride the funnel all the way to the end to land outside the office door. Go through and turn right. Search the desks for the disc, then have one of you pick it up and put it into the player on the other side of the room.

ACHIEVEMENT: Obstacle Building
This achievement is awarded for completing all test chambers in Course 04. If you've been doing the chambers in order, you'll get the achievement now.
END ACHIEVEMENT

Course 05: Mobility Gels

Upon completing Course 04, the entrance to the next course is pushed through the wall above the previous entrance. Directly across from it is a faith plate. Portal to the panel above it to bounce over to the entrance to Course 05. Check the chamber selector to ensure that Chamber 01 is selected, then head for the disassembly machines.

Chamber 01: "Repulsion Jumps"

B: Step onto the button to partially lower two lifts. This puts one of them near ground level.

O: There are two platforms with pedestal buttons on them; the lower one can be reached via portals, so portal up to it. Press the pedestal button to drop some repulsion gel at ground level. Drop down and go over to the gel. Bounce off it to land on the nearby lift.

B: Step off the button to raise your partner up to the platform, then go through your partner's portals to end up on the platform she was previously on.

O: Up here is the other pedestal button; press it to drop some gel on the lower platform near your partner. Jump down and step onto the button to lower the lifts again. This time, your partner is near the other one.

B: Bounce off the gel to land on the lowered lift.

O: Step off the button to raise your partner up to the dual door.

B: There's a panel opposite the door, shoot a portal there and the other portal at the ground floor.

O: Go through the portal your partner just made for you to join him.

Go through the dual door. There are no disassembly machines here, just a pair of color-coded chutes. Step into your respective chutes to get dumped to the next chamber.

Chamber 02: "Double Bounce"

As you enter, you'll see three fizzler walls. The leftmost one does not come all the way to the ground, ending at an upper platform. The center one is the largest. The rightmost one is small and leaves an open gap above it. Above that opening is an angled panel. To one side is a pedestal button which controls a blue gel dispenser with a panel below it.

B: Shoot a blue portal at the panel under the dispenser, then shoot a purple portal at the angeld panel. Press the pedestal button to dispense gel through your portal and create a blot of gel on the floor next to the left fizzler. Now look through the gap above the right fizzler to see a marked panel. Move the purple portal there.

O: Bounce off the gel and through the left fizzler to land on the upper platform. On the back of this platform is an excursion funnel located behind a grate. Shoot an orange portal on the panel where the funnel ends. Then turn around and look down to see two long platforms. The one that is further away (below the purple portal) is made of panels; shoot a red portal on it to extend the funnel straight up.

B: Press the pedestal button to dispense paint through the portal and into the funnel.

O: Move the red portal to another part of the platform allowing the paint to fall and splatter on it.

Continue this procedure until you've covered the platform with gel.

B: Press the button to load the funnel with paint again.

O: This time, instead of moving the red portal, put the orange portal on the panel next to the nearer platform. The funnel will disappear, dropping the paint through the portal and onto the other platform. Now stand on the button to raise a platform on the other side.

B: Hop off the blue gel and through the left fizzler to join your partner. Shoot a blue portal at the panel where the funnel ends. Take a running leap off the ledge and bounce off the gel on each platform to land on the other side. Move onto the green part of the far platform so that your partner can get off the button without dropping you. Turn left to see a marked panel; shoot a purple portal there to extend the funnel in front of the platform you're on.

O: Take a running leap off the ledge and bounce off the gel on the platforms as your partner did. You'll land in the funnel and be carried to the right, where you'll land on a catwalk. Follow it to your partner.

Head through the dual door and into the chutes.

Chamber 03: "Bridge Repulsion"

B: Across the way you'll see an exit sign. Turn left to see a hard light bridge. Shoot a portal where the bridge ends, then shoot the other one on a panel so that the bridge goes towards the exit sign and passes directly under the dispenser.

O: Walk out onto the bridge and look to the right to see a pedestal button. Line up with it, then shoot a portal at the end of the bridge and another one on the panel directly across from the button to extend the bridge out to it. Go press the button to drop blue gel onto the bridge.

Go to the gel and bounce off of it onto the platform by the exit sign. Go around the left side and through the dual door.

B: Step onto the bridge and shoot a portal on the panel where it ends. Walk up to it and you'll see another panel to the left; shoot the other portal there to extend the bridge through the fizzler. Note the nearby pedestal button.

O: Walk along the bridge through the fizzler, and shoot a portal on the panel where the bridge ends. To the left of that is another panel; shoot the other portal there.

B: Step over to the pedestal button and press it to dispense gel onto the bridge on your partner's side of the fizzler.

O: Bounce off the gel and onto the platform. Turn around and look down to see a platform under the gel spot. Shoot a portal there. Walk to the other side and you'll see a downward-facing panel above the bridge. Shoot your other portal there.

B: Press the button to drop gel through your partners portals and onto the bridge on your side. Go to the gel and bounce off it to join your partner.

Pass through the dual door and to the chutes.

Chamber 04: "Wall Repulsion"

B: Portal up to the platform across from the repulsion gel dispenser.

O: Shoot an orange portal under the repulsion gel dispenser. Look up at the ceiling and shoot a red portal at the angled panel there. Press the pedestal button to paint the tall metal plate on the wall. Move the red portal to the angled panel near the floor. Press the button again to paint the facing metal plate. Move the orange portal to the panel on the floor below the platform your partner is standing on.

B: Jump into the orange portal, which will bounce you between the two painted plates until you reach a platform at the top.

O: Portal up to the platform your partner jumped from.

B: Shoot a portal at the angled panel near the floor and the other portal at the panel on the floor under your partner's platform.

O: Jump into the portal on the floor to bounce up to your partner.

Proceed through the dual door.

B: Shoot a blue portal at the point where the hard light bridge ends. Shoot a purple portal onto the panel near the pedestal button, extending the bridge through the fizzler.

O: Walk through the fizzler to the end of the bridge. Shoot an orange portal under the blue gel dispenser there. Look up to see two angled panels; shoot a red portal onto one of them.

B: Press the pedestal button to dispense gel.

O: Move the red portal to the other panel.

B: Press the pedestal button again.

O: Jump onto the painted wall and bounce up until you pass through a fizzler and land on the upper platform. Turn to your right and walk out on the grating. Turn and face the gel dispenser, and shoot an orange portal under it. Then turn to your right and you'll see three panels suspended above the hard light bridge below. Shoot a red portal on the one furthest from yourself.

B: Press the pedestal button again. This time you'll paint the wall on the side of the platform your partner is standing on. Now move the purple portal to the middle suspended panel, the one facing straight down. This will create a vertical hard light surface.

O: Move the red portal to the suspended panel closest to yourself.

B: Press the pedestal button again to paint the hard light wall with gel. Go down the bridge until you're standing between the two painted surfaces. Jump into one of them and bounce up to the platform where your partner stands.

Head through the dual door and into your chutes.

Chamber 05: "Propulsion Crushers"

B: Shoot a blue portal at the panel facing the ramp. Shoot a purple portal under the propulsion gel dispenser. Press the pedestal button to spread the gel in a track up the ramp.

O: Run down the gel track and off the ramp to land on the upper platform.

B: Position yourself at the start of the gel track.

O: Trigger the timer on the ping tool. Press the button when it reaches "GO."

B: As soon as the timer reaches "GO," run down the track and catch the dispensed cube in mid-air. Place it on the button to open the exit door.

Proceed down the catwalk stairs and through the dual door to the next room.

B: Go stand next to the pedestal button.

O: Shoot an orange portal under the gel dispenser. Shoot a red portal at the nearby angled panel labelled "1."

B: Press the pedestal button to throw propulsion gel on the platform under the crushers.

O: Move the red portal to the opposite angled panel labelled "2."

B: Press the pedestal button again to paint the far platform.

O: Move the red portal to the panel above the alcove next to the panel labelled "1."

B: Press the pedestal button to paint the floor of the alcove. Then portal up to the alcove. Put a portal on each of the facing panels. The two facing portals form a virtual infinite track of orange gel. Run into the blue portal and keep going to build up speed.

O: Put an orange portal on the angled panel labelled "1." Wait until the crushers start to rise, then quickly replace the purple portal with a red one. This will launch your partner out the orange portal onto the platform.

B: You'll land on a gel track under some crushers. Don't stop! Run to the end. Then walk out onto the grating platform where you can see everything.

O: Portal up to the same alcove where your partner was running before. Place an orange portal on the panel which is closer to the gel dispenser, and a red one on the facing panel. Run into the orange portal and keep going to build up speed.

B: Shoot a blue portal at the angled panel labelled "2." Wait until the crushers start to rise, then quickly replace the red portal with a purple one. This will launch your partner out the red portal onto the platform. Now go stand on the button on your side.

O: You'll land on a gel track under some crushers. Don't stop! Run to the end and step on the button. With both partners on their buttons, a cube will be dispensed. Drop down, pick it up, and place it in the receptacle to open the exit door.

Proceed through the door and into the chutes.

Chamber 06: "Turret Ninja"

B: Drop a blue portal under the propulsion gel dispenser. Look towards the exit across the way. A little to the left of that platform you'll see an angled panel. Shoot a purple portal there. Press the pedestal button near the gel dispenser to spread gel on the runway opposite the angled panel. Press it again to get a good, solid coat. Now look towards the exit again. To the right of that you'll see a marked panel below a cube dispenser. Move the blue portal there. Now move next to the pedestal button you haven't pressed yet.

O: Use the nearby panel to portal yourself over to the runway. Stand at the end and face the fizzler.

B: Use the ping tool to start a countdown. When the timer reaches "GO," press the button to dispense a pivot cube, then aim at one of the two flat panels near the water. When you see the pivot cube fly out of the purple portal, move the blue portal to the flat panel you're aiming at.

O: When the timer reaches "GO" run down the runway and through the fizzler. Catch the pivot cube in mid-air and fly through the purple portal. Note that in order to get the "Talent Show" achievement, you'll have to do this right the first time. If you lose the cube at any point, you'll have to start the chamber over to get the achievement.

B: When your partner flies straight up out of the blue portal, quickly move the purple portal to the other flat panel. This will cause your partner to oscillate between the two portals.

O: As you fly into the air, you'll be able to briefly put the pivot cube into a laser beam. Try to aim the beam at the turrets to destroy them. You only have to hit a turret for a split second to destroy it, and the concussion can knock out other turrets on the same platform. Continue until you've destroyed them all.

B: Once all the turrets are gone, aim your crosshairs at the suspended panel which faces the exit door. Wait until your partner is in the air over the blue portal, then move the purple portal to that panel. This will fling your partner over to the exit. Then portal yourself over to the runway and stand at the end, facing the fizzler.

O: Upon landing, place the cube on the platform. Turn around and place an orange portal on the angled panel facing the runway. Then aim at the panel directly across from the exit door and shoot a red portal there.

B: Run down the runway and through the fizzler. You'll fling through your partner's portals and join them on the exit platform.

Proceed to the chutes.

ACHIEVEMENT: Talent Show
If you haven't lost a pivot cube, you'll earn this achievement at this point.
END ACHIEVEMENT

Chamber 07: "Propulsion Retrieval"

B: As you enter, note the two large panels on the wall at the left, one above the other, and an alcove to the right of that. Shoot a blue portal on the lower large panel. Turn right and shoot a purple portal under the propulsion gel dispenser, then press the pedestal button to spread a track of gel. Move the blue portal to the upper panel, then press the button again to spread more gel. Repeat the procedure with the two marked panels in the ceiling of the alcove to coat the floor between the two side panels.

O: Shoot an orange portal on the left side panel in the alcove and a red one on the right side panel. Note the angled panel above the alcove. Run down the track to the two pedestal buttons. Position yourself at the one on the right.

B: Stand in the alcove and run into the red portal. Keep going to gain speed.

O: Press the pedestal button to raise a large platform into place. It will only stay up a short time. Quickly run down the gel track until you have a clear shot at the angled panel. Shoot the orange portal there to fling your partner onto the platform. Quickly run back down the gel track and stand at the left pedestal button.

B: Run down to the end of the platform where the cube dispenser is.

O: When you partner is within a few steps of the dispenser, press the pedestal button to dispense a cube.

B: Catch the cube, then turn around and run back the opposite direction before you get dumped off the platform. Once you're safe, drop down and place the cube in the receptacle to the side of the fizzler.

Go through the opened door and into the chutes.

"Vault Entrance"

As the door leading into the next area opens, you'll see a turret at the far end of the platform. Some gel lands on it, causing it to bounce away, protesting "I need to protect the humans!"

B: Bounce off the gel puddle and through the fizzler. Shoot a portal on the angled panel on the other side, then walk over to the propulsion gel dispenser and shoot a portal under it.

O: Opposite the fizzler is another angled panel; shoot a portal there. Turn to face the door you entered from and you'll see a tall panel above it. Shoot the other portal at the bottom of this panel, then press the pedestal button. This will spread a trail of orange gel up to the puddle of blue gel.

B: Hop off the puddle of blue gel through the fizzler to join your partner.

Run down the track of orange gel and bounce off the blue gel to reach the catwalk on the other side. Go through the doorway and through the next fizzler.

B: Turn right and shoot a portal at the wall here. Across from the spot where you placed that portal, you'll see another section of wall illuminated; shoot the other portal there.

O: Go through your partner's portal. Follow the catwalk partly down the stairs, then turn around and you'll see an angled portal below. Shoot a portal there. Go back through your partner's portal. Turn left and walk past the entrance doorway, continuing to the broken end of the catwalk. Look down to see a flat panel. Shoot your other portal there and jump into it to fling yourself to the dual door.

B: Follow your partner off the edge of the catwalk and through the portal to join her at the dual door.

Proceed through to the next area and you'll see a large vault door. This is your ultimate goal, but it will be a bit before we get there. There is a long platform that goes out in the direction of the door. Note the blue gel dispenser above the end of the platform, and behind you and high up on the wall there's an opening in an orange gel pipeline.

B: Head off to the right, and use the two panels on the right-hand wall to portal past the gap. Pass through the fizzler. Ahead you'll see two panels with targets on them. Shoot a blue portal at the lower one. Turn to the left and put a purple portal under the orange gel dispenser and press the pedestal button to create a track of gel. Move the blue portal to the opposite wall and press the button again to complete the track.

O: Shoot an orange portal at the flat wall at the end of the gel track where your partner's blue portal used to be. Shoot a red portal at the target on the floor. Stand at the opposite end of the track from your portal, then run down it and through the portal to launch yourself into the air. Angle back downward to see a platform; quickly move your red portal to the wall there.

B: Go through the orange portal to arrive at the upper platform. At your left, you'll see a blocked inclined passageway with a pedestal button next to it. Press this button to dispense a cube. Turn around and shoot a blue portal on the panel facing this passageway.

O: Press the pedestal button near the gel dispenser, painting the cube with gel and causing it to slide down the incline. Then go through the orange portal to join your partner.

B: Past the hole in the floor you can see some panels on the wall. Portal over there with the cube.

O: Follow your partner through his portals.

On the other side you'll see two openings in the walls. Through one you can see two catwalk platforms, and two switches on the far wall. There are three gaps on the way to the switches, and the side wall labels them 1, 2 and 3. Laying flat against the wall under each of these is a platform, which can be raised into position when activated, allowing you to cross. The other opening has an arrow pointing out of it, and beyond this you can see a concrete wall.

O: Stand in front of the first gap, directly across from the left switch.

B: Portal over to the concrete wall with the cube. Here you'll find a long inclined passageway with three lasers across it. Stand at the top of this passageway, then release the cube so that it starts sliding down the incline. Quickly go back through the portal to join your partner, positioning yourself in front of the right switch.

When the cube slides down and interrupts the first laser, the corresponding platform will rise into place. As soon as it does, run onto it and keep going straight towards your switch. Keep in line with your partner so that you both reach your switches at the same time. Activate them as soon as you reach them. A moment later you'll be dropped onto a catwalk at the main level. If you have timed it properly, you'll hear an alarm bell sound, and orange gel will be dispensed onto the platform. However, you still need blue gel on the end to be able to make the jump to the vault door.

B: Nearby is a small doorway. Portal over to it, but don't go through yet.

O: Follow your partner through his portal.

Go through the fizzler and into the next room.

B: Shoot a portal at the panel where the excursion funnel ends. Shoot the other portal at the panel on the wall above the door. Stand on the button to reveal a panel on the far wall. Stay on the button.

O: Shoot a portal under the gel dispenser, and shoot the other at the panel in the ceiling. Press the pedestal button to drop gel into the funnel. Once all the gel is in the funnel, step through the large fizzler. Shoot a portal at the flipped panel on the far wall. Up and to the right of that panel is another one with lights above and below it; shoot your other portal there. This extends the funnel behind the divider, over the turrets.

B: When the gel has gone through your partner's portals and is over the turrets, step off the button. This will flip the panel, cutting off the funnel and dropping the gel on the turrets, causing them to bounce away.

Jump into one of the side walls and bounce back and forth between them to cross the chasm and land on a platform on the other side.

B: Hop up to the upper platform where the turrets were. Crouch in order to stop bouncing, then walk over to the far side of the platform. Look through the opening in the wall to see the excursion funnel. Shoot a portal at the platform where it ends. Stand on the button to reveal another panel high up on the wall; shoot your other portal at this panel. This should extend the funnel across the top of the room, passing above the divider. Stay on the button.

O: Hop up onto the upper platform where the turrets were and crouch to stop bouncing, but stay on this end instead of joining your partner. Shoot a portal on the high panel with the lights above and below it. Shoot the other one at the panel on the floor of the small landing next to this platform. Jump up off the gel and fall into that portal to be flung from the upper one. This will allow you to bounce much higher. Bounce across the platform and land in the funnel, riding it to another platform.

B: Step off the button and go back the way you came, crossing back over the chasm by bouncing on the side walls.

O: Walk to the window overlooking the main room. There's a pedestal button here; press it to see blue gel dispensed onto the end of the platform facing the vault door. Turn around and drop into the hole in the floor to join your partner on the lower platform.

Go back through the fizzler.

B: Portal back over to the main platform.

O: Follow your partner through his portal.

Run down the orange gel track and bounce off the blue gel at the end to arrive at the vault door. When both of you arrive, the camera will activate and look from one of you to the other. GLaDOS notes that the camera is connected to the vault lock and urges you to try something. To open the lock, you must perform a gesture which involves both partners, or each of you perform a solo gesture. Then sit back and watch the ending cutscene!

ACHIEVEMENT: You Saved Science
You receive this achievement automatically at this point.
END ACHIEVEMENT

Course 06: Art Therapy

The Art Therapy course is part of the "Peer Review" DLC which became available on October 4, 2011. It is accessed from The Hub by portaling over to the small compartment containing two buttons. Each of you stand on one button to be transported to the Art Therapy entrance area, where you can access the course selector, just as you would for the other courses.

Chamber 01: "Separation"

B: Stand on the button to the left of the chamber sign.

O: Stand on the button to the right of the chamber sign. This will open the doors leading to the next room.

Proceed into the next room, where a glass partition separates you from your partner.

O: Turn to the right and press the pedestal button to dispense a pivot cube. Pick it up and hold it in the laser beam. Redirect the beam through the glass and destroy the two turrets on your partner's side.

B: On the wall to your left as you entered is a panel; place a portal there. Place your other portal on the angled panel higher up on the left wall.

O: Put a portal on the panel on the floor below the cube dispenser. Place the other portal on the angled panel. Press the pedestal button; the existing pivot cube will fizzle, and a new one will drop through the portal on the floor, be lobbed through an opening in the glass partition, fall through your partner's portal and be dumped out onto the floor on the other side. Then go stand on the button.

B: Pick up the pivot cube that emerged from your portal. Walk to where the turrets used to be standing and across the bridge your partner raised.

O: When your partner is safely across the bridge, put one portal where the laser strikes the floor, and the other on the wall to the left of the angled panel. This will redirect the laser through the glass partition to your partner's side.

B: Use the pivot cube to redirect the laser back through the glass and destroy the two turrets on the other side. Then drop the pivot cube into the cube receptacle to open doors to the next area.

Walk through the doors and the corridors beyond into the next room, where you are again separated by a glass partition.

O: Note the angled panel in the middle of the goo moat. Beyond that is a platform, and above it is an illuminated checkerboard panel. Put a portal there, then put the other one in the nearby wall and walk through to land on the platform. Further on is another goo moat and another angled panel. Put a portal on both angled panels. Then go stand next to the fizzler, but don't go through yet.

B: Portal over to the ledge beyond the angled panel. Place a portal on the panel on the floor here, and put the other one on the angled panel.

These next actions will require you to work simultaneously and quickly:

B: With your partner waiting by the fizzler, press the pedestal button to release a ball. It will drop through your portal and be lobbed over the glass partition. As soon as it's through your portals, turn around and walk through the fizzler. There are two angled panels there; drop a portal on each, then wait for the ball to pass through them.

O: The ball lobbed by your partner will pass through your portals and be tossed back over the partition. As soon as it's through your portals, walk through the fizzler. Quickly turn left and shoot a portal at the panels on the far wall. Face forward again and shoot the other portal at the panel in front of you. Walk through and turn right. The ball you lobbed to the other side will pass through your partner's portals and get tossed straight to you. Catch it and put it in the ball receptacle.

B: Once the ball has passed through your portals, portal across the goo moat to the far side. The door here will open when your partner puts the ball in the receptacle.

Walk through the doors and rejoin your partner. Proceed through the dual doors and into the disassembly machines.

Chamber 02: "Triple Axis"

Walk down the stairs and along the catwalk. Avoid the crusher, then pass under it and through the fizzler. There are two short stairways here, one of which has a laser beam striking the top. Note also the two laser receivers, one above the fizzler on the wall and the other connected to a lift on the far side of the room.

O: Across from the fizzler's laser receiver on the opposite wall you see a horizontal row of panels, and at the left end there's an additional, higher panel. Place a red portal there. On the wall to the left of that there are several other panels, one of which is lower than the others. Put your orange portal there.

B: Put a portal where the funnel strikes the wall. Put the other portal on the wall directly below the orange portal, so that the funnel is redirected through the fizzler.

O: Pick up the pivot cube, then walk up the steps and hold the cube in the laser beam. Direct the beam through your portals into the laser receiver. This deactivates the fizzler through which the funnel passes.

B: Walk up the other stairs and hop into the funnel. Ride it through where the fizzler used to be. There's a hard light surface here; put one of your portals where it strikes the wall. Drop back down to the lower level and look closely at the wall on your left. The panel directly above your partner's portal is divided into smaller squares. Place your other portal on the left side of that panel. If you turn to face the laser beam, you will see that it passes close by it on the right. Then go and stand on the lift.

O: Put a portal where the funnel strikes the wall. Place the other portal on the wall to the right of that so that the funnel is redirected to pass through the laser beam and fall on the laser receiver for the exit. Pick up the pivot cube, then walk up the steps and into the funnel. Face forward and release the cube, then sidestep out of the funnel. Quickly walk over and join your partner on the lift.

The pivot cube will travel through your portals and be stopped by the hard light surface, redirecting the laser to the receiver and activating the lift. Upon reaching the top, proceed to the disassembly machines.

Chamber 03: "Catapult Catch"

B: Put a blue portal on the nearby panel. Put a purple portal on panel on the same wall on the far side of the room. Walk through the portal.

O: Follow your partner through the portal. Look towards the exit door and up to see a panel on the side of a suspended block. Put a red portal there.

B: Face across the goo moat with the fizzler on your left and you'll see another panel on the far side. Move the blue portal there.

O: Walk through the purple portal. Look up to see a panel on the opposite side of the same suspended block. Put an orange portal there.

B: Walk through the fizzler and portal up to the ledge. Put a blue portal on the angled panel you find here. Walk behind it to see a grating with an opening through it. Shoot a purple portal through that opening into the ceiling beyond. Hop through the blue portal and as you fall, shoot a purple portal into the floor and fall into it. You will be flung out the blue portal, through the fizzler, through your partner's portals and onto an upper ledge near where your partner stands. Press the pedestal button you find there. This will reveal an angled panel near the glass enclosure.

O: Just past and a little to the right of the glass enclosure, you can see some panels on the wall. Shoot a red portal there. Shoot an orange portal in the nearby panels and walk through.

B: Drop down to the lower level and walk through the orange portal to join your partner. Straight ahead is another platform with a faith plate; portal over to it and wait for your partner's signal.

O: Beyond the platform where your partner stands is another platform near the glass enclosure. Portal over it and walk through the fizzler into the glass enclosure. Inside you'll find a cube and another faith plate. Above the faith plate is a bull's-eye panel; put a portal there. Nearby there is a round opening in the glass; shoot your other portal through that opening onto the angled panel beyond. Pick up the cube and stand next to the faith plate. Start a countdown, and on "GO!" drop the cube on the faith plate.

B: When your partner's countdown reaches "GO!", step on the faith plate and catch the cube as it flies towards you from the right. You'll find a cube receptacle on the platform you land on; drop the cube in there to open the exit door.

O: Walk back through the fizzler and portal over to the platform with the other faith plate. Step on it to join your partner.

Walk through the exit door and head for the disassembly machines.

Chamber 04: "Bridge Gels"

Proceed along the catwalk into the next area.

B: Put a portal where the hard light surface strikes, and put the other portal on the panel to the left of that one. This will extend the hard light surface across the gap.

O: Drop a red portal under the repulsion gel drip. Repeatedly place the orange portal at various points along the panel strip on the left wall until you have thoroughly coated the hard light surface with gel. Repeat the process with the strip on the other side to coat the left wall. Move the red portal onto one of the panel strips so that gel stops coming out of the orange portal.

Leap into the gel coating the left wall to bounce back and forth across the gap. Note the doorway on the other side of the hard light surface. Jump onto the gel-coated panel on the floor and bounce over the hard light surface to reach the exit. Proceed down the stairs and through the dual door, then up the stairs and through the fizzler into the next room.

B: Shoot a blue portal onto the panel struck by the hard light surface. Turn around and shoot a purple portal at the lower nearby panel. This will extend a bridge across the room, but don't go across it yet.

O: Shoot a red portal under the propulsion gel dispenser. Shoot an orange portal onto the panel above the purple portal. This will coat part of the bridge in propulsion gel. Move the red portal to the ceiling panel above the bridge near the propulsion gel dispenser. Look to the left and move the orange portal under the repulsion gel dispenser. This will drop a patch of repulsion gel onto the bridge.

B: Run down the bridge and bounce off the repulsion gel to land on a platform. Pick up the cube you find there. Jump over to the lower platform with the button and put the cube on it to raise another platform near the exit door. Go back across the bridge and join your partner.

O: Near your orange portal is an angled panel which faces the vertical hard light surface. Move your red portal to that panel to coat the hard light surface with repulsion gel. Then move your orange portal to the higher of the two panels located below the exit platform.

B: Move your purple portal to the panel just below the orange portal. This will move the bridge under the repulsion gel dispenser, which will create a patch of repulsion gel there.

O: Move your red portal under the propulsion gel dispenser. This will coat the bridge with propulsion gel. Then move the red portal to the nearby panel. Run through it and down the bridge, bounce of the repulsion gel on the horizontal and vertical hard light surfaces and land on the exit platform above.

B: Follow your partner to the exit platform.

Go through the exit and proceed to the disassembly machines. They don't work, so you'll be dropped through the maintenance hole.

Chamber 05: "Maintenance"

Head up the stairs, and continue through three doorways marked "EXIT" until you encounter some disassembly machines, with a switch next to each one. Each of you stand in front of a switch and use a countdown to pull them simultaneously. This opens the maintenance holes in the disassembly machines; drop into them. Walk across the catwalk to where the conversion gel is leaking out of a pipe.

O: Put a red portal under the conversion gel leak. Put an orange portal on the gel near the edge so that gel is thrown across the gap and paints the floor of the next platform over.

B: Use the gel on the next platform to portal your way over.

O: Follow your partner through his portals. In the next area you'll see a catwalk along one wall on the left and another wall across from it. Continue moving the orange portal around to paint more surfaces until you are able to paint the surfaces of these walls. Move the portal back and forth between them to work the gel up the wall to the catwalk.

B: Pick up the cube and place it on a gel-covered area of the floor. Portal up to the catwalk using the gel laid down by your partner.

O: Go through your parter's portal to join him on the catwalk. Above the other walls is a column. If it's not painted with gel, put a portal on the wall next to you to throw paint onto it.

B: Portal up to the painted column.

O: Follow your partner through the portal. Make sure you've gotten a little gel on the floor, then put the orange portal on it to spread more gel to the far side of the platform. Then move the orange portal again to spray gel onto the other side of the column you painted earlier. Finally, put the orange portal on the newly-painted side of the column to throw gel over to the exit platform.

B: Put a blue portal on any nearby gel surface. Look down from the edge to find the cube you placed on a gel-painted part of the floor earlier. Drop a purple portal under it to bring it up to you. Put it down nearby.

O: You need to get rid of the turrets on the exit platform. Put the orange portal on the painted part of the exit platform to paint more of it. Keep moving the portal around, painting more of the platform, until you paint the floor under a turret. Then drop the portal under the turret to get rid of it. Continue until all three turrets are gone.

B: Portal over to the exit platform, bringing the cube with you. Drop it on the cube receptacle to raise the steps to the dual door.

Go through the door and follow the catwalk to the disassembly machines.

Chamber 06: "Bridge Catch"

B: Go over to the pedestal button and press it to dispense a pivot cube, then go stand in front of the faith plate which does not have a laser striking it.

O: Pick up the cube, then go stand in front of the other faith plate.

Do a countdown and step on the plates simultaneously. The cube should redirect the laser into a receiver at the apex of your flight, activating a hard light bridge under your feet.

O: Keep holding the cube and pointing the laser at the receiver.

B: Walk to the end of the bridge, passing above the fizzler. Put a blue portal on the panel at the end of the bridge.

O: Move the laser away from the receiver to deactivate the bridge. This will cause your partner to drop to the platform below, while you will bounce off the faith plate and come back up. Aim the laser back into the receiver to restore the bridge. Carefully put down the cube so that the laser still strikes the receiver.

B: Shoot a purple portal at the nearby panel.

O: Enter the blue portal to join your partner. Continue walking along the bridge through the fizzler and past the glass partition on the right. Shoot a red portal at the panel on the wall behind the glass partition.

Both of you drop to the floor below where the two faith plates are.

B: Press the pedestal button again. The previous pivot cube will fizzle, deactivating the hard light bridge, and a new cube will be dropped. Then go stand in front of the faith plate which does not have a laser striking it.

O: Pick up the cube, then go stand in front of the other faith plate.

Do a countdown and step on the plates simultaneously. You should again fly up and have the bridge appear under your feet.

O: Carefully put down the cube so that the laser still strikes the receiver. Shoot an orange portal on the panel at the end of the bridge.

Walk along the bridge through the dual door and the fizzler and enter the disassembly machines.

Chamber 07: "Double Lift"

Head down the catwalk into the next room. Some features to note here on this side of the room include a laser passing over a pit and an excursion funnel. A little to the right of the funnel is a laser receiver, and beyond that is a glass partition with a square hole near the top. Behind the glass is a pedestal button connected to a cube dispenser.

B: Shoot a blue portal on the high panel the funnel strikes. Shoot a purple portal through the square hole onto the panel on the ceiling beyond it.

O: Shoot a red portal high up on the wall opposite the funnel. Shoot an orange portal into the bottom of the pit.

B: Jump into the pit to be flung into the funnel.

O: As soon as your partner has passed through the orange portal, move it to the panel opposite the laser receiver. Note the panel being struck by the laser and watch your partner closely.

B: Face the wall as you descend the funnel, and press the pedestal button as soon as it is within reach. Immediately turn right and catch the falling pivot cube so that it doesn't fall into the goo.

O: As soon as your partner has activated the dispenser, quickly put a red portal on the panel being struck by the laser. This will reverse the funnel, saving your partner from a goo bath.

B: Ride the funnel back through the portal and sidestep out. Use the pivot cube to redirect the laser through the other glass partition and destroy the turrets on the other side. Aim the laser at the receiver to reverse the funnel again, then put it down. Turn left to see two panels on the wall, one facing the pit and the other to the left of that one. Shoot a purple portal at the left panel to direct the funnel through the fizzler. Then go stand next to that fizzler but don't touch it yet.

O: Walk through the other fizzler at the far end of the room; there will be a ball here. Across the goo pools you can see the funnel striking a panel on the left wall; shoot a portal there. Shoot the other portal on the panel on the end wall to extend the funnel across to you. Pick up the ball and hold it up. Jump upwards and release the ball into the funnel so that it travels down it to the other side.

B: When the ball is safely across, step through the fizzler. This will close your portals and cut off the funnel, dropping the ball. Quickly pick it up before it can roll into the fizzler or into the goo. Place the ball into the ball receptacle on the floor to deactivate the fizzler.

O: Step through the fizzler on your side. Walk to the other side of the room and note a ball receptacle on the wall. Shoot a red portal onto the checkerboard panel opposite the receptacle.

B: Restore the funnel by putting a blue portal on the high panel struck by the funnel and a purple one on the panel across from where the fizzler used to be. Pick up the pivot cube and pull it out of the laser so that the funnel reverses again. Put it down on the floor.

O: Walk over to the ball and shoot an orange portal at the panel struck by the funnel. Pick up the ball and step into the funnel. Ride it through the portal, then step out, still holding the ball.

B: Replace the red portal with your purple one, then take the ball from your partner.

O: Shoot a red portal on the panel struck by the laser. Shoot an orange portal on the panel to the left of that one. Take the pivot cube and use it to redirect the laser to the receptacle near the lifts. This raises the one closer to the wall. Now go stand on the other one.

B: Join your partner on the lift, then insert the ball into the funnel. When it settles into the receptacle, the lift you're on will rise.

O: Move one of your portals to interrupt the laser beam. This will lower the other lift to your level. Step onto it.

B: Join your partner on the other lift.

O: Return your portal to its previous location to restore the laser beam. This will raise the lift to the dual door.

Proceed through the door and along the catwalk to the disassembly machines.

Chamber 08: "Gel Maze"

The next chamber has you on an elevated platform with two buttons on it. One has a down arrow next to it, which lowers some blocks on the other side of the chamber. The other exposes a panel on the other side of a long runway.

B: Stand on the panel button.

O: Drop a red portal under the propulsion gel dispenser. Shoot an orange portal at the flipped panel. This will spread gel down the runway. Turn around and move the orange portal to the panel high up on the wall. This will paint the end of the runway right up to the panel. Move the red portal to the angled panel to the right of the orange portal. Turn back around and put the orange portal onto the panel at the end of the runway. Run along the gel and through the portal. You'll be lobbed across the room, through a fizzler and into an area behind a glass partition.

B: Put a blue portal under the repulsion gel dispenser. Turn around and put a purple portal on the angled panel behind you. This will lob gel across the room to an angled panel on the other side.

O: There are two angled panels here. The first is directly above a flat panel, and a laser is visible on the level above it. The second is at right angles to the first and is currently being splashed with gel. Put a red portal on the first and an orange portal on the second. This will splash repulsion gel on the wall opposite the first angled panel.

B: Step on the other button to lower the blocks.

O: The lowered block near you revealed a panel on wall on the other side. Move the red portal there. This should throw some gel on the floor. Bounce off it to reach the next level.

B: While still standing on the button, move the blue portal under the cube dispenser.

O: Press the pedestal button to release a pivot cube. It will drop through your partner's portals and fly through the fizzler. As long as it keeps getting fizzled, the dispenser will continue to supply replacements. Drop down to the lower level and stand on the button to disable the fizzler. When the cube flies into your portal on the angled panel, go get it.

B: Stay on the button. Move the blue portal under the propulsion gel dispenser. This will start flinging propulsion gel across the room.

O: Near the button you were just standing on are two panels, one above the other, one angled and one flat. Put down the cube and move the red portal to the lower panel. This will create a runway of propulsion gel. Put an orange an orange portal on the angled panel above the red portal. Pick up the pivot cube and stand at the far end of the runway, then run into the red portal. You'll bounce off the patch of repulsion gel on the wall and land on the upper level where the laser is. Use the pivot cube to aim the laser straight through the glass at a row of panels.

B: Looking down and to the left, you should see some turrets guarding a laser receiver and the exit. Across from them is a row of panels. Move the blue portal to the spot struck by the laser, and the purple one to the row of panels across from the exit. Adjust the purple portal as needed to destroy the turrets, then adjust it again to get the laser to strike the receiver. This will open the exit door.

O: Drop down to the lower level and stand on the button to deactivate the fizzler. Across the room you can see some panels on the ceiling. Put a red portal on the ceiling there. Put an orange portal on the nearby panel and go through. Move the orange portal under the repulsion gel dispenser to drop some gel on the floor, then bounce off of it to reach the exit door.

B: Bounce off the gel to join your partner at the exit door.

Continue forward to the disassembly machines.

Chamber 09: "Crazier Box"

Proceed down the hall into the room. Notice the cube up on the elevated glass box with a floor made out of metal grating. Your objective in this room is to paint the cube with repulsion gel to break it out of the box.

There are three glass booths. One contains a button and a repulsion gel dispenser, one has two levels of platforms in it, and one contains a button and has a fizzler across one side.

B: Walk through the fizzler on your right and turn right to see a hole in the glass. Shoot a blue portal onto the wall on the other side of the glass.

O: Follow your partner through the fizzler and go to the other side of the short hallway. Here's another hole in a glass panel; shoot an orange portal through it onto the wall on the other side. Shoot a red portal on a nearby wall.

B: Walk through the red portal. Shoot a purple portal onto the floor under the gel dispenser, then stand on the button to dispense the gel. Then walk back through the portal.

O: Go back to the other glass panel, through which you can now see a patch of gel on the floor. Shoot an orange portal through the hole onto the wall on the other side.

B: Walk through the red portal and bounce off the gel patch to the upper level. Here you can see another hole in the glass, and through it some panels in the ceiling covered with metal grating. Shoot a blue portal there, then drop down to the lower level and go through the orange portal.

O: Move your orange portal back into the room with the gel dispenser.

B: Walk through the red portal and stand on the button.

O: Walk back through the fizzler and note the gel drip on the left. Drop a red portal under that drip. To the right is another set of panels on the ceiling. Shoot an orange portal there to create a patch of gel on the floor. Bounce off the gel patch and over the fizzler to land on the other side. Stand on the button to flip the panel below the glass box. Shoot an orange portal onto that panel to paint the cube. Walk through the fizzler back into the main area.

B: Portal out of the room and walk through the fizzler back into the main area.

Both of you try to catch the cube when it breaks out of the glass box before it falls into a fizzler. For the purposes of this walkthrough, we will assume that Blue catches the cube.

O: Go to the same gel patch that you bounced off of before to go over the fizzler. However, this time use it to jump up to the nearby platform where there is another fizzler. Walk through it and stand on the button to deactivate it so your partner can bring the cube through.

B: Bounce off the gel patch onto the platform and wait for your partner to deactivate the fizzler, then walk through to join her.

In this room, you need to 1) wash off the cube, 2) put it on the cube receptacle, and 3) reach the dual door.

B: Hold the cube in the laser beam to block it. This partially lowers the nearby lift.

O: Portal up to the lift.

B: Pull the cube away to restore the beam. The lift will rise again. Put the cube down and allow it to bounce around the room. Shoot a blue portal into the floor below your partner. Shoot a purple portal into the panels across from the fizzler. Catch the cube again, then stand near the entrance to the room.

O: Jump (not fall) off the platform into the blue portal to be flung through the fizzler and onto the platform behind it. Here you see a water dispenser and a pedestal button which activates it. Place a portal on the floor under the dispenser and the other on the wall. Press the button to dispense some water.

B: Hold the cube in the water stream to wash it off, then put it down in the laser beam to lower the lift again. Move the purple portal to the wall panel next to the cube receptacle.

O: Go through the fizzler and drop down to the ground. Portal up to the lowered lift.

B: Follow your partner through her portal and join her on the platform. Move the blue portal under the cube on the floor. This will restore the laser beam, raising the lift, and at the same time dumping the cube into the receptacle, which unlocks the dual door. Shoot a purple portal on the angled panel below you, then jump into the blue portal to fling yourself to the dual door.

O: Follow your partner through the blue portal and join him at the dual door.

Walk into the next area. After the lights go off and back on, walk through the opening into a large room.

B: Straight forward is a brightly illuminated wall; put a blue portal on it. Put a purple portal on the nearby panel and walk through.

O: Look up and you'll see a platform on the right with a short segment of catwalk extending over the edge. That's where you ultimately need to go. Across from it is a wall; put a red portal up there, then drop down to the bottom level.

B: Look up and to the right and you'll see two cement walls. The front one has a red portal on it, and there's another one behind it. Move the purple portal to the back wall. The blue portal's too high to reach from where you are now, so drop down to the bottom level where your partner is. Move the blue portal to the cement patch you find there and go through.

O: Follow your partner through the blue portal. Turn right and walk behind the wall that has the red portal on the other side and up to the edge. Look down and shoot an orange portal on the floor. Drop into it to fling yourself to the last platform.

Go through the gate and down the catwalk to the large double doors. Enjoy the ending cinematic!

ACHIEVEMENT INDEX

Missing an achievement? This index will let you easily look it up and find out how to achieve it.

Automatic Single Player Campaign Achievements

This section lists all the achievements that you will have received automatically if you complete the single player campaign. For details about a particular achievement, go to the indicated part of the single player walkthrough.

Bridge Over Troubling Water

Complete the first Hard Light Bridge test

• Chapter 3, GLaDOS Test Chamber 11

Drop Box

Place a cube on a button without touching the cube

• Chapter 2, GLaDOS Test Chamber 06 (chance #1)
  
• Chapter 3, GLaDOS Test Chamber 13 (chance #2)
  
• Chapter 8, Wheatley Test Chamber 01 (automatic)

Dual Pit Experiment

Do the same test twice

• Chapter 8, Wheatley Test Chamber 01

Lunacy

That just happened

• Chapter 9, Wheatley's Lair

SaBOTour

Make a break for it

• Chapter 4, GLaDOS Test Chamber 21

Stalemate Associate

Press the button!

• Chapter 5, GLaDOS's Chamber

Stranger Than Friction

Master the Propulsion Gel

• Chapter 7, Beta Test Chamber 03

Tater Tote

Carry science forward

• Chapter 6, Beta Test Area

The Part Where He Kills You

This is that part

• Chapter 9, Part 1

Tunnel of Funnel

Master the Excursion Funnel

• Chapter 8, Wheatley Test Chamber 15

Undiscouraged

Complete the first Thermal Discouragement Beam test

• Chapter 2, GLaDOS Test Chamber 01

Vertically Unchallenged

Master the Repulsion Gel

• Chapter 6, Alpha Test Chamber 03

Wake Up Call

Survive the manual override

• Chapter 1, Relaxation Chamber

White Out

Complete the first Conversion Gel test

• Chapter 7, Gamma Test Chamber 01

You Monster

Reunite with GLaDOS

• Chapter 1, GLaDOS's Chamber

Missable Single Player Campaign Achievements

This section lists achievements which are possible to miss, having completed the single player campaign. To learn how to get a particular achievement, go to the indicated part of the single player walkthrough.

Door Prize

Examine all the vitrified test chamber doors

• Chapter 6, Aperture Lobby and Testing Spheres (1, 2 & 3/6)
  
• Chapter 6, Beta Test Area (4, 5 & 6/6)

Final Transmission

Find the hidden signal in one of the Rat Man's dens

• Chapter 2, GLaDOS Test Chamber 06

Good Listener

Take GLaDOS's escape advice

• Chapter 4, GLaDOS Test Chamber 22

No Hard Feelings

Save a turret from redemption

• Chapter 5, Turret Testing Area

Overclocker

Complete Test Chamber 10 in 70 seconds

• Chapter 3, GLaDOS Test Chamber 10

Pit Boss

Show that pit who's boss

• Chapter 9, Wheatley Test Chamber 17

Portrait of a Lady

Find a hidden portrait

• Chapter 7, between Beta Test Chambers 01 and 02

Preservation of Mass

Break the rules in Test Chamber 07

• Chapter 2, GLaDOS Test Chamber 07

Pturretdactyl

Use an Aerial Faith Plate to launch a turret

• Chapter 2, GLaDOS Test Chamber 06 (chance #1)
  
• Chapter 3, GLaDOS Test Chamber 15 (chance #2)

Scanned Alone

Stand in a defective turret detector

• Chapter 5, Turret Testing Area

Schrodinger's Catch

Catch a blue-painted box before it touches the ground

• Chapter 6, Alpha Test Chamber 05

Ship Overboard

Discover the missing experiment

• Chapter 6, Beta Test Area

Smash TV

Break 11 test chamber monitors

• Chapter 8, Wheatley Test Chamber 01 (1/11)
  
• Chapter 8, Wheatley Test Chamber 02 (2/11)
  
• Chapter 8, Wheatley Test Chamber 03 (3/11)
  
• Chapter 8, Wheatley Test Chamber 04 (4/11)
  
• Chapter 8, Wheatley Test Chamber 05 (5 & 6/11)
  
• Chapter 8, Wheatley Test Chamber 06 (7/11)
  
• Chapter 8, Wheatley Test Chamber 11 (8/11)
  
• Chapter 8, Wheatley Test Chamber 12 (9/11)
  
• Chapter 8, Wheatley Test Chamber 15 (10/11)
  
• Chapter 8, Wheatley Test Chamber 16 (11/11)

You Made Your Point

Refuse to solve the first test in Chapter 8

• Chapter 8, Wheatley Test Chamber 01-A

Automatic Co-op Campaign Achievements

Below are all the co-op campaign achievements that you are guaranteed to get if you complete all the co-op courses. Note that none of these achievements requires you to do the course in one sitting.

Bridge Building

Complete all test chambers in the Hard-Light Surfaces co-op course

Confidence Building

Complete all test chambers in the Mass and Velocity co-op course

High Five

Celebrate your cooperative calibration success
You get this one automatically at the end of the Calibration Course.

Obstacle Building

Complete all test chambers in the Excursion Funnels co-op course

Team Building

Complete all test chambers in the Team Building co-op course

You Saved Science

Complete all test chambers in all courses of co-op
You do not have to complete the "Art Therapy" chambers (as they were not yet available when this achievement was released). As soon as you've completed all of the chambers from all five of the original co-op courses at least once, you'll earn this achievement.

Missable Co-op Campaign Achievements

Below are all the achievements that you might miss when completing the co-op courses.

Air Show

Perform 2 aerial gestures before touching the ground in co-op
You can do this anywhere you're airborne for more than a couple of seconds. This includes long flings, infinite falls through portals, and travel through excursion funnels. Simply press the gesture button while airborne to perform a gesture. (There's no menu to select from, so all you do is press it.) Then do it again before you hit the ground.

Asking for Trouble

Taunt GLaDOS in front of a camera in each of the five co-op courses
This does not include the Calibration Course nor Art Therapy, only the courses accessed via the main part of The Hub. Any dual door will have a camera mounted on it; a light appears on the camera when you are in range. Simply perform a gesture while in view of one of these cameras. Do this in front of at least one camera in all five courses to earn the achievement.

Can't Touch This

Dance in front of a turret blocked by a hard light bridge in co-op
The first opportunity to earn this very easy achievement is in Course 03, Chamber 06. The co-op walkthrough notes times when you can earn this achievement.

Empty Gesture

Drop your co-op partner in goo while they are gesturing by removing the bridge under them
Any course with hard light bridges and goo will serve for this achievement. The earliest available opportunity is in Chamber 1 of the hard-light surfaces course. Just extend a bridge out over the goo, then have your partner stand out there and perform a gesture. While they're doing it, move the bridge to dump them into the goo. Then be a sport and take the dunk for them in return.

Four Ring Circus

Enter 4 different portals without touching the ground in co-op
The key word here is "enter": exiting a portal doesn't count, you have enter all four portals. There are several different techniques for doing this. I describe the easiest one I know in the walkthrough for Course 2, Chamber 04.

Friends List With Benefits

While playing co-op, hug 3 different people on your friends list
Pretty straightforward: just hug three different friends at least once. Note that if you hug a stranger that you connected with through Steam's matching service, it doesn't count. Friend them first if you want, then hug. (You don't really go around hugging strangers anyway, right?)

Gesticul-8

Perform all 8 gestures of your own volition in co-op
As you advance through the co-op chambers, you'll unlock gestures. You'll know you've unlocked one when your robot performs it automatically. This one won't count towards the achievement, so just perform it again yourself whenever it happens. You'll earn the achievement when you've done all eight. Note that dual gestures initiated by the other player do not count towards this achievement for you. You do not have to do them all in one sitting.

Iron Grip

Never lose a cube in Chamber 6 of the Mass and Velocity co-op course
To achieve this, you must catch the cube on your first attempt in the latter part of the chamber. If you mess up and it falls in the goo, you must restart the entire chamber.

Narbacular Drop

Place a portal under your co-op partner while they are gesturing
This achievement is named for the student game that was the predecessor of the Portal franchise. It would be more accurate to say that you must place a portal under your co-op partner--CAUSING THEM TO FALL INTO IT--while they are gesturing. Simply putting one under them when you haven't placed the other end won't do it. This can be done in most chambers; just have your partner stand on a portal-accepting surface, and place one of your portals somewhere nearby. Then have them gesture, and drop your other portal under their feet while they're doing it to earn the achievement. Be nice and return the favor.

Party of Three

Find the hidden companion cube in co-op test chamber
This is found at the end of the last chamber in Course 04. See the walkthrough for that course to get a description of how to accomplish it.

Portal Conservation Society

Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
See the walkthrough for the course to get a description of how to accomplish it.

Professor Portal

After completing co-op, complete Calibration Course online with a friend who hasn't played before
The Calibration Course is the area you ran through before the first time you encountered The Hub, the one that started by having you select a favorite animal or element. Once you've completed co-op, all you have to do is find someone on your friends list who hasn't done co-op yet and play with them. The Calibration Course will come up automatically, and finishing it with them will earn you the achievement. Make sure you've friended them before starting the Calibration Course.

Rock Portal Scissors

Win 3 co-op games of rock-paper-scissors in a row
You can do this achievement when either partner has unlocked the rock-paper-scissors gesture, which happens at the beginning of Chamber 04 of the Team Building Course. (So yes, it's entirely possible to earn this achievement without having unlocked the gesture, but your partner will have to do all the work.) There doesn't appear to be any way to influence the outcome, so you'll just have to keep playing it until you win three times in a row. A tie doesn't count, but it doesn't break your streak, either. It's completely random, so you may earn it quickly, or you may have to play it for a while. About 50% of players will get a streak of three after 15 throws or less. For exhaustive details about how that statistic is computed, see the section analyzing the achievement below.

Still Alive

Complete Course 4 with neither you nor your co-op partner dying
This is probably the hardest achievement to get, if the Steam achievement stats are anything to go by. It is suggested that you practice together with a buddy rather than try to achieve this with a random stranger. There aren't any special tips for this achievement other than to follow the steps given in the walkthrough carefully and don't die. If you do, you will have to repeat the ENTIRE COURSE from the first chamber, which is particularly frustrating when you die in the last one!

Talent Show

Never lose a cube in Chamber 6 of the Mobility Gels co-op course
This achievement was introduced on July 7, 2011 and is only available if both players are using the PC or Mac version of the game. To achieve it, the player running down the goo runway must catch the pivot cube on the first attempt and not lose it afterward. If you fail, you must restart the chamber and try again if you want the achievement.

Triple Crown

Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
For most people, the three chambers that are easiest to do in under a minute are 02, 03 and 04. Your best bet on this one is to practice with one specific friend, focusing on those three chambers until you accomplish it. Note that at any time you can invoke the menu to go back to The Hub to start the course over. You do not have to do all three in the same sitting; the game keeps track of your best time on each chamber, and as soon as three chambers in the course have times under 60 seconds, you'll get the achievement.

An Analysis of the Rock Portal Scissors Achievement

Just how long will it likely take to get this achievement? The short answer is that 50% of players will get the achievement with 15 throws or less. How'd I get at that answer? Well, if you're willing to endure the impending rampant nerdiness, continue reading.

In any single round of rock-paper-scissors, there are nine possible combinations. However, there are only three outcomes (player 1 wins, player 2 wins, or tie) and all three are equally likely, as illustrated in the table below, with player one's throws along the rows and player two's throws along the columns:

	Rock	Paper	Scissors
Rock	tie	P2	P1
Paper	P1	tie	P2
Scissors	P2	P1	tie

For the achievement, you need to get a streak of three wins. It can be thought of as a state machine with four states: no wins, 1 win, 2 wins and 3 wins. The diagram below illustrates this state machine:

            +--------+
            |        |
            V        |
       /---------\   |
+----->| No wins |---+
|      \---------/ tie or loss
|       win |
|           +--------+
|           |        |
|           V        |
| loss /---------\   |
+------|  1 win  |---+
|      \---------/ tie
|       win |
|           +--------+
|           |        |
|           V        |
| loss /---------\   |
+------| 2 wins  |---+
       \---------/ tie
        win |
            |
            V
       /---------\
       | 3 wins! |
       \---------/

After each throw, one-third of the people with no wins will move up to 1 win, while the remaining two-thirds stay at no wins. One-third of the people with 1 win or 2 wins will move up to the next level, one-third will stay where they are, and the remaining third goes back to no wins. Since the goal is 3 wins, everyone already at that state stays there. So the number of people in each state after n throws can be expressed mathematically as:

        2[w0(n-1)] + w1(n-1) + w2(n-1)
w0(n) = ------------------------------
                      3

        w1(n-1) + w0(n-1)
w1(n) = -----------------
                3

        w2(n-1) + w1(n-1)
w2(n) = -----------------
                3

                  w2(n-1)
w3(n) = w3(n-1) + -------
                     3

This is the part (or perhaps it's even earlier?) where real mathematicians and I probably diverge in terms of coming to the solution. The folks with the math doctorates will likely do something elegant at this point to produce the solution. I, being an unwashed commoner, will unceremoniously plug the formulae into a spreadsheet and have it crank out a bunch of rows. Say we had 27 people playing. Here's how the first three throws turn out:

Throw	0	1	2	3
0	27	0	0	0
1	18	9	0	0
2	15	9	3	0
3	14	8	4	1

So one-third of the 27 people (9) won the first throw, one-third of those (3) won the second throw as well, and one-third of those (1) won all of the first three throws. If we convert these numbers to percentages and continue on, we eventually get:

Throw	0	1	2	3
15	27.1%	14.7%	8.0%	50.2%

This is the point where the percentage of players having reached three wins in a row crosses the 50% mark. If we take the three wins column and plot it, we get this:

% of players achieved
100% +                                                                     ____
     |                                                 _____----------'''''
 90% +                                        __----'''
     |                                 __---''
 80% +                             _--'
     |                         _--'
 70% +                      _-'
     |                    _/
 60% +                 _-'
     |               _/
 50% +              X
     |            _' \
 40% +          _/    \
     |         /    Midpoint: 50% have
 30% +        /    the achievement with
     |       /       15 throws or less
 20% +      /
     |    _/
 10% +   /
     |  /    34.4%     62.2%     78.2%     87.43%    92.6%     95.8%     97.6%
  0% +----+----+----+----+----+----+----+----+----+----+----+----+----+----+---
     0        10        20        30        40        50        60        70
                               Number of throws

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License

This document is licensed under Creative Commons BY-NC-SA 4.0[creativecommons.org].

[rjwut]

@Bosser111: Thanks for pointing out that Pit Boss is missing from the index; I'll fix it soon. How were you able to get past Wheatley's first chamber without getting Drop Box?

[Bosser111]

Going through this has been so helpful!!
Did notice though that Pit Boss isn't in the index and Drop Box shouldn't be in the automatic section, I've played this game multiple times and didn't get that achieve till actually trying for it while following this guide

[TomatoRadio]

Impressively Complete. Good job!

[Minek-ill]

This is amazing, thank you!

[mulch eater]

would have*

[mulch eater]

ok i wouldve done someone like say "instructions unclear i turned off the cooling systems to my local nuclear power plant and caused 1000+ deaths" but holy shit

[s⛩rin3]

Absolute perfect. Nice job on this guide mate.

[Blue]

holy moly, must have taken 10 years to write this. nice job. :)