As a result of Homer's unfortunate tumble down the stairs, he finds himself confined to bed rest, while Marge, seeking vengeance on Bart, assigns him the dreaded task of cleaning his room. In the midst of this chore, Bart stumbles upon an old cherry bomb, and with a sparkle of mischief in his eye, he decides to flush it down the school toilet—totally unaware of the impending chaos this will cause, particularly for Principal Skinner's mother, Agnes Skinner, who just happens to be in the adjacent girls' restroom. The ensuing explosion sends Agnes flying, igniting Principal Skinner's fury and prompting him to devise an excessive punishment for Bart.
Skinner’s solution? Bart will join the school’s student exchange program and be sent to France for three months. Initially hesitant, Bart is ultimately lured in by the promise of residing in a "lovely French château," much to Skinner's satisfaction. Meanwhile, back in Springfield, the Simpsons welcome their own exchange student, Adil Hoxha from Albania, who effortlessly charms the family with his demeanor and eagerness to lend a hand.
However, Bart's French adventure turns out to be nothing like the dream escape he imagined. Upon arriving at Château Maison, he discovers he is consigned to a dilapidated vineyard, where he is forced into grueling labor by winemakers César and Ugolín. His days transform into a blur of exhausting tasks that include hauling water buckets, harvesting grapes, and stomping them underfoot. As time drags on, Bart's spirits plummet, stripped of adequate food and freedom.
Back in the Simpson household, Adil injects a breath of fresh air into the family dynamic, particularly charming Marge with his refined manners and willingness to help. Homer sees a chance to connect with Adil as he shows him around the nuclear plant—blissfully oblivious to Adil's covert agenda involving a fax machine hidden in Bart's treehouse, transmitting sensitive designs back to Albania.
As Bart’s predicament worsens, he decides to take initiative. A visit to town for antifreeze turns into a moment of desperation, as he seeks out a police officer to share his plight—only to find that the officer lacks any English understanding, leaving Bart feeling infuriated and powerless. But then, something miraculous occurs: Bart unexpectedly begins speaking fluent French, passionately explaining his suffering at the hands of the winemakers and their plot to sell contaminated wine. The authorities act quickly, arresting the winemakers and celebrating Bart as a hero for unmasking their deceitful practices.
Back in Springfield, however, Adil's secret activities are dramatically uncovered by the FBI, triggering a series of events that lead to his immediate deportation to Albania as part of a tense prisoner swap. In an intriguing subplot, an American spy is freed from Albanian detention, though the reasons for his captivity remain shrouded in mystery. Meanwhile, Bart returns home to Springfield, laden with vibrant souvenirs he’s eager to present to his family. But his excitement is soon quashed as he becomes the object of his father Homer’s (misguided) pride. Homer mistakenly believes Bart has become fluent in French, a notion swiftly debunked when it’s revealed that the only thing Bart managed to articulate was the insult “buffoon” directed at his oblivious father.
