A disembowelled body is discovered in a sewer. The team must establish whether a killer is at large, or if feral swine have returned to London's sewers. Chandler has to pull the detectives together after an abysmal team-building exercise.

Cast: Geoff Bell, Ben Bishop, Ed Cooper Clarke, Phil Davis, Damian Dudkiewicz, Michael Fitzgerald, Rob Hall, Charlotte Hope, Eliza Jones, Matthew David McCarthy, Muna Otaru, Steve Pemberton, Rupert Penry-Jones, Angela Pleasence, Claire Rushbrook