Nearing the completion of his sentence in Sing Sing prison, Paul Vitti's life is threatened by assassins while incarcerated. He fakes insanity and starts singing showtunes from West Side Story to get the attention of Ben Sobel, who had previously hung up on him while attending his father's funeral.
The FBI calls in Ben to see if Paul is really insane. It turns out that Vitti is faking it, but Ben doesn't find this out until after he's left Sing Sing. Needing some therapy himself after his father's death, a grieving Sobel talks Vitti into finding a regular job (per FBI request). Vitti attempts to find a legitimate job (he tries his hand at a car dealership, a jewelry store and a restaurant), but his rude manners and paranoia mess things up.
At the same time, he also discovers that the Rigazzi family are the ones who want him dead. He reacts to this by telling the Rigazzis that he is 'out', and seeking a new line of work. He finds employment working as a technical advisor on the set of a Sopranos-like mafia TV series. Meanwhile, FBI agents inform Sobel that Vitti has his old crew back together, and may be planning something big. This rouses Sobel's suspicion, and he visits Vitti, the two get caught up in a car chase, which ends in Vitti escaping. The FBI blames Sobel, and gives him 24 hours to track down Vitti.
After locating Vitti (through Sobel's own son Michael, who now works as Vitti's chauffeur), Sobel discovers that Vitti is planning a big heist. He tries to talk Vitti out of it, but Vitti goes ahead and Sobel is forced to go along. The crew score $20m in gold bullion, but some of Rigazzi's thugs take over. Sobel in a fit of anger defeats one of them and Vitti's men take care of the rest. They use the $20 million in gold bullion to frame the Rigazzi family leaving the Rigazzi goons locked in a truck suspended from a crane. This leads to the arrest of the entire Rigazzi family, and in turn, prevents a mob war.
Sobel meets with Vitti and Jelly on a bridge, and they part ways again as friends, singing another West Side Story showtune together.