Hubert Franier, an honest hospital extern, should never had got into trouble had he not been infatuated with Véra, a beautiful but stupid creature, who led him down the wrong path. Because of her and her friends, Hubert, who naively thought he was taking part in a practical joke, was actually a party to a car theft. Because of him, Monsieur Pierre, a good-natured caretaker, is in hospital. Racked with remorse, Hubert decides to hide from the police and finds refuge at his friend Louis'. Louis is a very sociable artist and his flat is the meeting place of many a colorful character. There, Hubert gets to know Candy, a Black American saxophonist, as well as Boubou, a Black little boy. He also meets Marie-Lou, a bar girl who dreams of becoming a nurse.