At the end of a particularly bad day, Bart gets caught in a downpour and loses control of his skateboard. He crashes down a flight of stairs into the Legitimate Businessman's Social Club, which is actually a mobster hangout. The mobsters, Fat Tony, Louie, and Joey, are impressed with Bart's spunk and give him a job tending bar. Marge finds out what Bart is doing, and asks Homer to intervene. Homer pays the mobsters a visit and likes them so much, he asks if they can give Lisa a job, too.

When Fat Tony finds out that Principal Skinner is making Bart stay after school, the mobsters pay Skinner a visit. the next day, Skinner is missing. After dreaming that Skinner is killed by the mobsters, Bart confronts Fat Tony. When the police burst in, Fat Tony pins Skinner's disappearance on Bart, who is thrown in jail and put on trial.

As Bart is about to be convicted, Skinner rushes in, telling the court that he has been stuck in his basement since a stack of newspapers crashed down on him the week before. A free man, Bart quits his job, having learned that mobsters make lousy friends.