I.D.

John and his colleagues are assigned to infiltrate Shadwell Town's violent football firm. They pose as painters and decorators and begin frequenting The Rock pub, where they befriend Linda and start to blend with the regulars. They also start attending matches with known hooligans as part of their undercover plan.

During a pub crawl, the group clashes with Arsenal fans in a brutal brawl. The incident exposes the brutal code of the hooligan environment and pulls John deeper into the violence. His initial distance from real-life consequences begins to blur.

John runs after a bus of Midchester fans heading to a game and the Shadwell firm follows, ambushing the bus in traffic. The bus attack sees Bob praising John's leadership and labeling him a hero. The violent act cements John's status within the firm and distances him from his old life.

John becomes intoxicated by the hard-drinking, hard-fighting culture. He starts prioritizing match days and fights over his marriage and job, letting the undercover mission consume him. The emotional toll and creeping paranoia begin to strain his relationships.

The Shadwell gang travels to Wapping for a FA Cup clash and attempts to provoke a fight among the home crowd. Trevor panics at the sight of a machete and flees, while John is drawn back into the fray, ultimately being hailed as a hero by the gang. A full-scale brawl erupts and he is briefly led away by police before breaking free and rejoining the Shadwell end.

Marie plans a beach holiday but their argument triggers a separation, and John begins an affair with Linda in a drunken stupor. The double life erodes trust with his wife and strains all his relationships. The undercover mission's toll manifests in personal betrayals.

At Tyneburn, a standoff turns deadly when objects are thrown and Gumbo is injured by a dart; Martin and Nik attempt to climb the fence but are knocked back by the police. The firm chases Tyneburn fans into a deserted market where a fatal stabbing occurs, with CCTV later reviewed to reveal John's involvement. Trevor erases the footage to spare him from conviction.

Back at The Rock, Bob introduces John to Wynton, who hints at using him in the underworld and hands him drugs. This moment plants the seed that John is being drawn further into criminal activity rather than policing. The lines between officer and offender begin to blur.

The undercover operation is wound down and the team is commended, but they are told to return to beat duties in their divisions. Trevor warns that any of their targets spotting them in uniform could spell danger or death. The sense of closure clashes with the reality of what John has become.

An official from the licensing department thanks the team for their evidence and announces that The Rock has been shut down. Linda confronts John at her home, resenting him for destroying her world and admitting she always knew he was a policeman. The revelation worsens John's isolation.

John sinks into alcoholism and his marriage deteriorates; his attempts to reconcile with Marie are rebuffed and his in-laws confront him forcefully. He returns home to a trashed house, overwhelmed by guilt and addiction. The downward spiral marks the breakdown of the undercover mission and his identity.

The closing sequence shows John at a Neo-Nazi march, still immersed in his undercover persona. Trevor watches, trying to understand what he has become, but John rebuffs him and performs a Nazi salute, mouthing Sieg Heil. The scene makes it clear that John cannot escape what the role has done to him.