When Bart flushes a cherry bomb down the toilet, Principal Skinner suggests that he should partake in a foreign exchange scheme. Bart is transferred to France, working for some criminals that spike wine with antifreeze. Meanwhile, back in Springfield, Adil Hoxha, an Albanian boy, is exchanged to the Simpsons to receive in the scheme, shows an interest in the power plant, and sends information back to the Albanian government.
Having being forced to clean his room (after accidentally causing Homer to trip and fall down the stairs, hurting his back), Marge and Lisa arrive home to find an injured Homer. Marge tells Bart to clean his room. While doing so, he discovers an old cherry bomb, and chooses to flush it down the boys' restroom toilet at school in an attempt to pull a prank. This decision is unknowingly made at the same time as Principal Skinner's mother, Agnes Skinner, visits the school. Bart shows Milhouse, Lewis, and Richard the cherry bomb, and plans to flush it. When Agnes goes into the girl's restroom, Bart detonates the Cherry Bomb in the boys' restroom, not knowing that Agnes is in the other restroom, and gets thrown off her seat caused by the toilets' gushing.
Shortly afterwards, Principal Skinner arrives at the Simpsons' house with Bart in tow. Skinner explains that the incident has 'transcended incorrigible.' Feeling that detention, suspension or expulsion won't do, he suggests deportation. The idea shocks Marge, but Skinner explains his plan: In order to be rid of him, Skinner proposes to the Simpsons that Bart should participate in a foreign exchange program. Bart is sent to France, whereas the Simpsons host a student from Albania named Adil Hoxha.
In France, Bart is greeted by two winemakers named Cesar and Ugolin, who work him worse than their donkey. After snooping into Bart's clothes and items, Bart is made to collect and crush grapes, sleep on the floor, and test wine adulterated with antifreeze.
Back at the Simpsons, it is revealed Adil is actually a spy who is after nuclear secrets, which he intends to obtain from Homer. Homer is happy that Adil is taking an interest in his work, and promptly shows him around the plant.
Back in France, Bart is sent out for a case of antifreeze. As he wanders the streets, he finds a police officer, who is not fluent in English and only gives Bart a piece of candy, Bart leaves, feeling that he will never learn French, even though he has been there for two months. He then suddenly starts speaking French, and tells the officer about the child abuse and how they put the antifreeze in the wine. Cesar and Ugolin are swiftly arrested for the antifreeze in the wine, and Bart becomes a national hero in France.
Back in the USA, Adil is caught by the FBI and is exchanged for a boy who is an American spy caught in Albania. As Adil leaves, Bart returns, and his family is grateful to see him again. Bart has purchased gifts for the family, which Lisa dubs "His first unselfish act."