While goofing around in the Springfield Elementary steam tunnels, Millhouse and Bart accidentally start an explosion which destroys Principal Skinner's new used car. Homer is forced to miss a Moe's Tavern sponsored trip to Vegas and drive his son to a juvenile delinquent boot camp. During the arduous trip, the duo bond and Homer keeps his son from hard time. Meanwhile, Marge is arrested for selling their old prescriptions during a yard sale.