Despite the German occupation of Paris, 17-year-old Antoine Michaud (Alain Delon) is having the time of his life. In this atmosphere of chaos and oppression, Michaud is in the midst of a torrid affair with Yvette Grandmaison (Françoise Arnoul), a woman old enough to be his mother. But as Michaud turns to black market dealings to finance Grandmaison's expensive tastes, the teenager struggles to hide his true motivations from his father, Charles (Bourvil) -- a war profiteer in his own right.
