Feathers McGraw was a lodger, renting a room with Wallace when he had financial issues. Not satisfied with the room on offer, McGraw moves into Gromit's room, forcing him to live in a doghouse. McGraw then proceeds to irritate Gromit further by playing music loud late at night, hogging the bathroom, and monopolizing Wallace's time. Thinking Wallace has forgotten him, Gromit sadly leaves the house.

Seeing Gromit gone, McGraw removes the controls on the techno-trousers to control them and arranges for Wallace to slide into them when he slid down to breakfast the next morning. McGraw then takes Wallace on a remote-controlled 'walk' to test his new control of the trousers. While searching for a place to live, Gromit notices Wallace trapped in the techno-trousers and follows. Gromit observes McGraw with the remote controlling Wallace and also spots a wanted poster of a disguised McGraw. Following McGraw to the museum, Gromit witnesses him take measurements for the break-in.

Gromit returns to the house to his old room and finds blueprints to the museum's blue diamond exhibit. Feathers, disguising himself with a red rubber glove (revealing himself to Gromit that he is the criminal chicken from a wanted poster he saw earlier), outfits the now sleeping Wallace a helmet with a claw and walks him to the museum, sending him through the air vent, inside to the diamond room, walking on the ceiling. There, using the electric claw to snatch the diamond, he tries to walk Wallace back out. However, a loose roof tile causes Wallace to sway off balance and trip one of the lasers, setting off the alarms.

McGraw walks Wallace home and forced him into the wardrobe; Gromit attempts to intervene, threatening McGraw with a rolling pin, but the penguin holds Gromit at gunpoint and forces him into the same wardrobe with Wallace. Gromit hotwires the trousers to stomp continuously until the wardrobe's floor paneling broke off, allowing them to break free. The two try to catch Feathers as he attempts to evade them with their electric train set.

After a long battle with the penguin, Wallace and Gromit manage to trap him in a milk bottle. They then return the diamond as their award and turn McGraw over to the police, who has officially imprisoned him in the zoo for good.