The family goes to a magic-themed restaurant. While there, Marge gets drunk on Long Island Iced Teas and Bart becomes so fascinated with magic that he buys a magician's kit from the gift shop. On the way home, a sturgeon falls from the sky (implicitly from the space station Mir) onto the family car's hood, which is severely damaged. Homer and Bart start their magic show as a way to make money, but the act becomes a failure, and Homer leaves Bart to do the rest of the act on his own. Bart is left out on the street, and people begin giving him money so he can get home on public transportation.
As Homer drives home, he sees Bart in a taxi, and when he gets home he sees him eating a steak dinner. They decide they can make money grifting, however Marge and Lisa begin suspecting of them after they "worked" without Bart's kit, which they both left behind at home. Homer and Bart continue to grift after they have fixed the car, and Grampa volunteers to help them grift, since he was a con-artist during the Great Depression. Grampa, Homer and Bart grift the residents at the Springfield Retirement Castle. While performing the grift, they are arrested by an FBI agent. When Homer and Bart get to jail, they realize the FBI agent himself is a con man, and conned them out of their money and the car.
Homer and Bart say the car was stolen in the church parking lot. The next morning they are surprised however to learn that Groundskeeper Willie was arrested for stealing the car, as he matched the description they gave of the carjacker as a "foreign loner with a wild, bushy hair". Not wanting to admit they were conned, Homer and Bart go along with Marge's theory. At the trial, the Blue Haired Lawyer leads Homer to say that it was Willie who stole the car. After Willie is proven guilty, he snatches Wiggum's gun and shoots Principal Skinner. At this point Homer finally confesses that he got conned but Marge and the townspeople themselves tell Homer and Bart that they set up the trial and the carjacking to teach them a lesson on conning people, revealing that Skinner was not really shot (it was a fake blood pack), the judge was Grampa wearing a latex mask, and the con man who stole their car was an actor called Devon Bradley. As Lisa is ready to explain why the town, media and police officials had "nothing better to do" than show them the consequences of their actions, Otto runs through the courtroom doors, shouting, 'Surf's Up!'. The scene then cuts to Springfield at the beach, with characters from the episode surfing, including the waiter from the restaurant, the two astronauts from the Mir space station and the sturgeon swimming in the sea.