Georges Lajoie is a Parisian café owner. As every summer, Georges, his wife Ginette and grown-up son Léon go on holiday to Loulou's campsite, where they meet up with the Schumacher family (whose father is a bailiff) and the Colin family (who sells bras in the markets). This year, their peace is slightly disturbed by the proximity of a construction site where foreign workers are employed. Xenophobic comments are made. One evening at the ball, a fight breaks out between Lajoie, Albert Schumacher and two algerian immigrant workers...

The story centers around a graduating class of "less-gifted" students in a private Versailles high school. Only a miracle has brought the students this far along, and after a practical joke misfires and the whole school is dynamited, the students are in deep trouble. They have to present themselves in court for their punishment and it could not be worse: If they don't pass their high-school graduation exams, they go to prison!