When he crashes his skateboard into the stairwell of the Legitimate Businessman's Social Club, Bart falls in with a particularly bad crowd: the Springfield Mafia. Soon, he befriends Fat Tony, Louie, Joey and other goodfellas, who take him on as their bartender and errand boy. As Bart adopts more and more gangster-like traits, Marge grows anxious. Meanwhile, Principal Skinner disappears and the police strongly suspect that Bart and his new friends are responsible. During the sensational trial, Fat Tony turns stool pigeon and rats out Bart as Skinner's killer. Nobody can save Bart but Skinner himself, who emerges from his hiding place to explain that neither Bart nor the Mob did anything to him.