While messing around in the school’s steam tunnels, Bart and Milhouse trigger a massive escape of steam that destroys the school. Although Milhouse is free to go, Principal Skinner proposes that Bart be sent off to "Upward Bound", a behavioral modification camp for troublemaking children. Meanwhile, Moe announces that he is treating Homer, Lenny, Carl and Barney with renting a minivan and taking them on a trip to Las Vegas, after a failed suicide attempt led to him suing the rope company that made a faulty noose and earning a hefty settlement. While Homer is near the Moe's Tavern, the luggage is packed and loaded into the minivan. Homer says that he is taking Bart to the airport and then coming to go to Vegas. Homer then takes Bart to the airport to send him to the camp in northwest Oregon (flying by way of Portland). However, at the airport, it is discovered that Bart is on the No Fly List after an incident in Atlanta where Bart unbuckled his seat belt before the plane could come to a complete stop. Homer decides to drive him to the camp instead, but is annoyed at having to miss the Vegas trip with Moe and his bar buddies.
During the ride, Homer angrily blames Bart for missing his Vegas trip. While they are stopped at a roadside diner, Bart pretends to respect Homer in order to escape; his plan works and he heads off home. However, he then reluctantly rescues Homer from almost driving off of a cliff and they are soon back on the road, now with Bart chained and duct-taped in his seat, Homer now not able to trust his son. Meanwhile, Marge and Lisa have a yard sale. It is initially a total failure until Otto discovers that Marge is selling the family's expired prescription drugs. Although reluctant, Marge soon makes lots of money selling prescription drugs, but Chief Wiggum eventually discovers the scheme and arrests her. Homer gets Bart to the camp, and leaves him there as Bart sadly watches Homer drive away. As he drives to Las Vegas, Homer begins to feel guilty, and decides to bring Bart back. Meanwhile, Bart is thoroughly enjoying his stay at the camp, and begins to realize he does not have to feel good by doing pranks, until he sees Homer run down a horse with his car, who leaves with Homer to go to Las Vegas, in return to washing the horse's blood off the car.
Lisa returns home from school and gets two phone messages: one from Marge begging Homer for bail money and another from Homer, who made it to Vegas, but ended up in prison for fighting with a pit boss and losing track of Bart. Lisa tells Maggie that she anticipated the day when the two of them would be the only members of the family left to fend for themselves and states that she will look for work in the morning.