After postman Eric Bishop crashes his car driving the wrong way round a roundabout, his friends at the sorting office try to cheer him up. But Eric has too many things on his mind, especially problems with sons Ryan and Jess. Eric keeps a life-size poster of former Manchester United centre-forward Eric Cantona on the wall and asks its advice. One day, he finds the real Cantona standing behind him.
Eric tells Cantona about meeting Lily in 1979, at a 1950s rock'n'roll dance contest. They had a daughter, Sam, but Eric left them, and has felt intense guilt ever since. The roundabout incident was caused by confusion after he agreed to pick up Sam's baby daughter Daisy from Lily, and he couldn't face meeting her. Cantona orders Eric to shave and go to see her. Eric meets Lily and apologises.
After discovering a stolen cement mixer in front of his house, Eric finds Ryan and his friends going to see Manchester United versus Barcelona, and travelling in a glossy black Mercedes.
Eric tells Cantona more about his life. He still keeps a postcard of a Picasso peace dove, sent by Lily shortly after his departure. He wants to write to her, but can't articulate his feelings.
Eric and his postman friends watch the match in the pub. One, Spleen, is an outspoken FC United member, and he argues about his motives with fans who have stayed loyal to Manchester United. Returning home, Eric sees Ryan being beaten up by local gangster Zac.
Eric is unable to get through to Ryan and Jess, and Cantona tells him that it's because he's a poor disciplinarian. Eric reminisces about Cantona's great goals, but Cantona says his proudest moment was a pass to goalscorer Denis Irwin against Spurs. He tells Eric that if he always plays safe, he will never take any risks. During his nine-month ban for assaulting a fan, Cantona learned the trumpet, and plays a shaky rendition of 'La Marseillaise' over the Manchester rooftops.
Lily brings Daisy around to Eric's house, but cries after seeing that he's kept the Picasso card. Eric hands the baby to an alarmed Jess and rushes after her. She reminds him that he walked out on her and Sam and refuses to speak to him.
Cantona tells Eric that the noblest vengeance is forgiveness. Lily rings him immediately afterwards and asks to meet him in a pub. During a long heart-to-heart, Eric confesses that he had a panic attack during Sam's christening. Lily tells him that she thought he'd gone off her. Sam is surprised to find her parents having a friendly chat. Back at Eric's house, Cantona orders him to start a fitness regime with him as his personal trainer.
Deciding to spring-clean his life, Eric throws out lots of junk. But when he finds a gun in Ryan's room, he realises that his son is in serious trouble. Ryan comes home, the two fight, and Ryan goes off with the gun. Eric and Jess borrow fellow postman Meatball's car and try to find him. They see the aftermath of a nightclub shooting, but no sign of Ryan.
Ryan returns the next day, and Eric demands to know what's going on. Ryan is looking after the gun for Zac, and can't go to the police because Zac's heavies have threatened to set their dogs on Jess. Eric goes to see Zac, but is humiliated by his Dobermann.
During a family reunion with Lily and Sam, Eric's house is raided by armed police and everyone is arrested. A furious Lily refuses to speak to Eric, though Ryan is relieved to find that he's hidden the gun in a chicken. Video footage of Eric's humiliation is posted on YouTube.
Cantona advises Eric that it's impossible to outrun people faster than himself, and that he should exploit Zac's fears. Eric hatches a plot with his friends to go round en masse to Zac's house, disguised in Cantona masks, smash up his Mercedes, television and furniture, spray him and his associates with red paint and threaten to post footage on YouTube. Finally, Meatball destroys the gun with a sledgehammer.
At Sam's graduation, Lily and Eric are reconciled.
