Fiftysomething dental surgeon François (Robert Stack) leaves his loving wife and three children in order to enjoy a life free of responsibility, beginning a relationship with a much younger woman, Catherine (Anicée Alvina), who confesses that she is also having an affair with Marc (Frédéric Meisner), a motorcycle-riding man her own age. Undeterred, François befriends Marc and gets his own motorcycle, but when he suffers an accident, he is forced to confront the limitations of his aging body and the reality of his waning youth, harsh realities counterposed to undying hope in this frank, human film.