Plot

Top dog Gromit springs into action to save his master when Wallace's high-tech invention goes rogue and he is framed for a series of suspicious crimes.

Gromit's concern that Wallace has become over-dependent on his inventions proves justified, when Wallace invents a "smart gnome" that seems to develop a mind of its own. As events spiral out of control, it falls to Gromit to put aside his qualms and battle sinister forces - or Wallace may never be able to invent again.

Tapping into modern day fears over automation, the film will focus on Gromit's concern that Wallace has become over-dependent on his inventions, which proves justified when Wallace invents a "smart gnome" that seems to develop a mind of its own. As events spiral out of control, it falls to Gromit to put aside his qualms and battle sinister forces or Wallace may never be able to invent again.

Gromit's worries about Wallace becoming overly reliant on his inventions prove to be well-founded when Wallace creates a 'smart gnome' that appears to develop a mind of its own. As it becomes clear that a mysterious figure from the past might be behind the chaos, Gromit must step in to confront the sinister forces at play and save his master, or Wallace may never invent again.—Oscar Serpa

Wallace invents a robotic garden gnome, Norbot, and creates a new business venture where he hires it out to work in other people's gardens. His faithful canine pal, Gromit, feels left out. Meanwhile, Feathers McGraw, the criminal penguin Wallace and Gromit apprehended after he stole the Blue Diamond from a museum (in "The Wrong Trousers") is imprisoned in the West Wallaby Zoo, and when he hears about Norbot on television, he hacks into Wallace's computer and re-programs the gnome to serve him and create his own army of garden gnomes.

While working in various gardens, the gnomes steal several objects and the police's chief inspector Albert Mackintosh conclude that Wallace is behind it and confiscate most of his possessions except the gnomes which they cannot find. Gromit reclaims Wallace's gnome tracking device from the police station and tracks down the gnomes to the zoo where be discovers they have used the objects to build a submarine for Feathers to escape in via the sewer network. Feathers spots Gromit and has Norbot cut him from the tree he is hiding in. They both fall to the ground and the impact resets Norbot to his original settings.

Gromit goes to the museum where the diamond is being put back on display but it has been replaced with a turnip - Feathers hid the diamond in Wallace's old teapot when he was caught. Upon returning home, Gromit is captured along with Wallace by the gnomes, and Feathers recovers the diamond from the teapot and locks them both up in the closet.

Wallace and Gromit escape and pursue Feathers down a canal on narrow-boats. After a big chase, Feathers escapes into Yorkshire on a train but Gromit has switched the diamond again with a turnip, and Gromit returns the real diamond to Chief Mackintosh. Wallace returns to inventing while Gromit accepts Norbot into their home.