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...