To enter the sewers, power must be turned on and a Green Card must be found. The Green Card has three locations, each in a red dumpster:

• Between spawn and the Stamin-up area (on Stamin-up side)
  
• In the Juggernog area, next to the truck
  
• In power, at the end of the alley

Once the Green Card has been acquired, it can be swiped at the Green Card Scanner in spawn. The door next to it will open, and a button inside can be pressed that will open the sewer entrances in spawn and the Speed Cola area.

Down the sewer tunnel that has the HMLMG is a door; interact with it to knock and you will get some dialogue from a Mysterious Survivor asking for food.

To do this, get 25 kills around the grill in the Stamin-up area. Once all 25 have been killed, the meat will cook for one minute, at which point it can be collected and returned to the Mysterious Survivor.

Now you must retrieve some water for the Mysterious Survivor. This requires picking up an empty Water Jug near Speed Cola, and then filling it for 30 seconds at a Large Water Catcher located on top of the building near Electric Cherry.

To access this area, you must first retrieve the Blue Card, which can be found in the supply drop that arrives in spawn on Round 10. After opening the Blue Card door,

Once the water jug has been filled, return it to the Mysterious Survivor.

Now the Mysterious Survivor will need some weaponry; you can provide him with almost any bullet weapon, but will not be satisfied with all of them.

Once he is satisfied, he will tell you which kind of ammunition the weapon will take (either Pistol Bullets, 5.56 Rifle Ammo, or 12 Gauge Shells). Now you must search three Loot Crates around the map to find the correct ammunition (the locations don’t change, but the ammunition inside is randomized each game):

• On the side of the train opposite spawn
  
• Across the bridge from Mule Kick
  
• In power on top of two crates

After obtaining the proper ammunition, return it to the Mysterious Survivor.

Now you must obtain some Low-Grade Fuel. To start, you must destroy three Crude (red) Barrels around the map with any of the four melee weapons (starting Hatchet, box weapons, or wallbuy Mace on the wall above Double Tap) and collect the Crude Oil they drop.

Note: you can utilize the trade table near Juggernog to temporarily store a weapon

Barrel locations:

• In spawn, between a telephone pole and flaming barrel
  
• In spawn, on the train
  
• In the Stamin-up area, next to the piano
  
• In the Deadshot area, under the train
  
• In the Juggernog area, next to the car at the near end of the street
  
• In the Juggernog area, down the alley and next to the Oil Refinery
  
• In the Juggernog area, next to the car at the far end of the street
  
• In the garage next to Electric Cherry
  
• In power, under the truck
  
• On the opposite side of the transformer where the Loot Crate from the previous step spawns
  
• On the same level as PhD, under the stairs leading up

Once all the crude oil has been obtained, it can be refined at the Oil Refinery mentioned above (down the alley near Juggernog). After it has been refined, it can be picked up and returned to the Mysterious Survivor.

Now you will be tasked with finding something dangerous; to this end, the Mysterious Survivor will provide you with a red card. This can be used at the red scanner at the top of the map, which will reveal a small room with a Locked Crate.

All players must interact with the Locked Crate to start hacking it, which will initiate a two-minute lockdown, so be prepared.

Once the lockdown is finished, the crate will unlock and allow the player to pick up launch codes, which can be turned to the Mysterious Survivor.

Now that your next destination has been set as Launch Site, you will need some protection from the heavy radiation that is present there. To this end, the Mysterious Survivor will provide you with some parkas that should be converted into Hazmat Suits.

Once the parkas have been picked up, a piece of hazmat cloth can be found randomly dropped by a zombie once per round. Make sure to pick up the parkas or the hazmat cloth will not start dropping

After all cloth pieces have been collected, the parkas can be repaired and reskinned into Hazmat Suits at the Repair Bench located near Deadshot.

Once the Hazmat Suits have been acquired, they can be returned to the Mysterious Stranger.

Now that you have all you need, the Mysterious Stranger believes he can get you out through another door located in the room he’s been trapped in. He will provide you with a fuse in order to figure out a solution.

Now, two switches must be flipped over the span of 30 seconds, but each switch is locked behind a door that can only be opened with the fuse; the fuse can be picked up and placed as many times as needed in order to complete this step. There are two lights found next to the Blue Card Scanner that will indicate whether or not a switch is still active. One door is located next to Mule Kick, while the other is near the Oil Refinery.

Once both switches have been pulled in time, both doors will open and remain open, and the door next to the Research Table/Blue Scanner will open. In this room are two buttons; the one on the right can be interacted with to complete the step.

Note: the upgraded M249 or HMLMG are recommended for this fight

Upon returning to the Mysterious Survivor, he will test the back door to make sure it opens; however, this will trip an alarm and cause the front door to be permanently closed. With him separated from you, he will give back the Low-Grade Fuel and ask you to find a way to meet him at Launch Site.

Now all players must go back to the room where they unlocked the door and interact with the second button. This will fail to open the gates, and will instead close off the sewers and call in an Attack Helicopter, which must be defeated to progress.

The Attack Helicopter will go to five different locations, and must be damaged at each of these locations in order to defeat it (damage is indicated by hitmarker sounds).

Note: Unfortunately, explosives cannot damage the helicopter

Once defeated, it will spin out of control and crash, destroying the debris to the Helicopter on the roof. If you have already picked up the Low-Grade Fuel (if missed earlier, the same drawer you put it into earlier will now be open with it in it), the Helicopter can then be used to escape.

It is highly advised that you complete the main ending first before completing the alternate ending as the alternate ending skips the boss fight

To achieve the alternate ending, only one thing needs to be done differently: when you arm the Mysterious Survivor, give him the Advanced Waterpipe Shotgun. Now when you unlock the back door, he will use the A.W.S. to shoot down the front door, allowing you to escape with him.

First. the Blue Card must be obtained and it's respective area opened. Now, jump across to the roof next to Mule Kick (can be done from the end of the bridge or near the turret) and pick up a blueprint for an Advanced Waterpipe Shotgun that is sitting in a corner.

The blueprint can be research at the Research Table next to the Blue Card scanner. After it is researched, it can be picked up and the three parts necessary to build the A.W.S. can now be picked up.

The pipes can simply be found in spawn, between the Mystery Box spawn and the door leading to Deadshot.

The metal can be acquired by first picking up a propane tank in the power area (at a jump-up section near the free perk), and then taking it to Deadshot and recycling it in the Recycler (the only one that's open).

Once the propane tank is done recycling, you can pick up metal and scrap; the scrap will be used for the third and final part.

Once the scrap has obtained, you can use it at the only available Vending Machine (in power, on the side of the white shipping container). This will send out a drone that will return in about a minute with gunpowder.

Once all three parts have been obtained, the A.W.S. can be crafted at the Workbench near Juggernog (this will take 30 seconds). Once picked up, it can be re-obtained from the Mystery Box if it is ever discarded.

There are three speakers located around the map that, once picked up, can be placed on the table next to the piano. Once placed, the Easter Egg Song can be toggled on and off.

Locations:

• In a trash pile next to Deadshot
  
• On top of a barrel near the Oil Refinery
  
• Under one of the tables near the Roulette Wheel

For this, you will need to have Dead Wire on a weapon. Now, shoot the sparking portion of the telephone pole in spawn closest to the big door and continuing shooting the spark until it gets to the pole near Speed Cola. Once the last one has been hit, a noise will be heard, and a Max Ammo will spawn below the pole that will last for the rest of the game.

There are three teddy bears around the map that, once shot, will reward all players with a free perk and extra perk slot.

Locations:

• On the balcony above Speed Cola
  
• On a debris pile behind the wall to the left of the power switch
  
• Underneath the helipad

In the power area, there is a floating Random Perk Powerup locked behind a chained door. These chains be shot with the Advanced Waterpipe Shotgun (only initially available after completing its buildable quest mentioned above), after which the door will open and the free perk can be picked up.

Once you have progressed to the fuse part of the Main Easter Egg, a loading bay key can be found on a shelf in the fuse room near the oil refinery.

Once picked up, it can be used to open the door next to the truck in power. There will be a pallet blocking your patch; shoot it with a weapon that has Blast Furnace equipped and after a few seconds it will be destroyed. Press the button behind it and the garage door will open; inside are an M249 and M4 that can be picked up for free.