Louise has been a widow for years and teaches literature in a high school. She divides all her time between books and her son, Martin, who still lives with her. During a family lunch, she meets Martin's best friend, Stanislas, a young painter of Russian origin, who is studying at the Beaux-Arts and whose talent promises a brilliant career. Louise is still finding Stanislas very attractive and already the young man is madly in love with her. All it takes is a little something to bring the two lovers together in the same passionate embrace. Informed by his mother, Martin pretends to be delighted by this unexpected rapprochement between the two beings he loves the most. His rage bursts, however, during the family meeting that Louise has organized to make her affair with Stanislas official.

To be closer to his children following his divorce, Laurent Monier, a history and geography teacher in a peaceful provincial high school, accepts a position in a sensitive college in the Paris suburbs. He is assigned the hardest class, the fourth techno, and he finds an apartment in the Cité des Muriers, a particularly difficult district.

Divisional Inspector Bricot sends two detectives to the French Riviera to dismantle a drug deal in a carnival mask factory. However, knowing the low efficiency of his subordinates' work, he goes down to Nice to conduct the investigation.

Five young conscripts lead a peaceful life in the barracks of a small town. Their officer is an eccentric man who lets them spend their time listening to music. The atmosphere changes completely with the arrival of a new officer who wants to prepare them for major maneuvers.