Simon Garden is a well-meaning but ineffectual probation officer who, haunted by hypoglycemia, is transferred to Manchester. There, he finds himself drawn to a striking WPC, Emma, and his professional life begins to tilt toward something personal and unexpectedly hopeful.
Shortly after, Kirsty — a young juvenile delinquent — crashes her car after a police pursuit and is rescued by Detective Inspector Burton. Burton charges her with concealing Class A drugs in a toy, and Kirsty protests innocence. As Simon handles the case, he grows suspicious of Burton when he notices the toy in Burton’s possession.
That night, after following him to a nightclub, Simon discovers that Burton is corrupt when he witnesses Burton murder an accountant who threatened to expose his drug involvement. The moment reveals a dangerous blend of charm and criminality beneath Burton’s polished exterior, and Simon narrowly escapes, but not before he loses his wallet in the chaos.
The next day, Simon learns Burton is leading the murder investigation and threatening to frame him. Disheartened, he plans to leave Manchester. But a television interview with Burton makes Simon realize the nightclub’s CCTV footage could prove his innocence, and that the CCTV tape was deposited into the West Clyde Bank by the nightclub’s owner. Seizing an opportunity, Simon enlists help for a bank heist from three of his earlier success stories back in Blackpool: George, Jeff, and Colin. When they stumble upon Kirsty trying to steal a television, they reluctantly admit her into the plan, partly out of a sense of camaraderie and partly because she offers useful help.
For the heist, Colin devises a computer virus to trigger every security alarm in the city, and a robot designed to disable the bank vault’s time lock; the latter is planted inside the vault and records a vault code used by a staff member. To ensure a clean getaway, the group stages a protest by cyclists to create gridlock around the city center, complicating any police pursuit. As they train together, the team slowly bonds and becomes a tight-knit unit.
However, when Emma questions Burton about the accountant’s murder after Simon reveals what he witnessed, Simon’s house is raided by the police. He is shocked when the accountant’s severed head is found in his kitchen, and the group is arrested. Kirsty manages to escape and rescue the others, and they decide to proceed with the heist despite the mounting danger.
Reaching the bank, the group breaks in and overcomes the security measures, only to discover the bank code won’t work. Their plan hits a snag when a disguised Victor, who faked his death, reveals that the code won’t work while the alarm is active, forcing them to wait until it deactivates before they can gain entry into the vault. Inside, Simon recovers the CCTV tape, but the others steal a shoulder bag of cash that Burton had received for his corrupt activities. They flee as the police arrive, aided by the cyclists’ gridlock in the city center.
Simon proceeds to Manchester City Hall to interrupt Burton’s award ceremony, but is confronted by Burton’s men. Emma helps to stage a hostage situation to publicly expose Burton’s crimes, and the tape is finally played after Victor—posing as a police officer—arrives with the evidence. Burton is arrested along with his men, and the crowd cheers Simon’s action. In the celebratory chaos, Victor slips away with the stolen cash, while Simon and Emma share a long-awaited kiss.
