Gérard is an engineer who is married to Gabrielle and has a nine-month-old son, for whom he cares deeply. When his wife leaves him for feminist reasons, he is left with custody of their son. To satisfy his romantic longings, Gerard embarks on an affair with Valérie, his son's daycare worker. However, Gabrielle fights for custody of the child, and when Gérard's affair with Valérie threatens his custody chances, Gérard responds by mutilating himself.