The story takes the Fenouillard family to Paris where they want to see the Eiffel tower;but they take the wrong train (after the laborious explanations of the station master),winds up on a ship who sails away to Brazil.
While their parents are busy shopping in a department store, Tiennot, who would rather chase girls, buys the complicity of Bébert, his little brother. In the train on the way back home, ...