Prof. Henri Laborit uses the stories of the lives of three people to discuss behaviorist theories of survival, combat, rewards and punishment, and anxiety. René is a technical manager at a textile factory and must face the anxiety caused by corporate downsizing. Janine is a self-educated actress/stylist who learns that the wife of her lover is dying and must decide to let them reunite. Jean is a controversial career-climbing writer/politician at a crossroads in life.

Recovering from an attempted suicide, a man is selected to participate in a time travel experiment that has only been tested on mice. A malfunction causes the man to experience moments from his past in a random order.

Marguerite loses her wallet, and it's found by Georges, a seemingly happy head of family. As he looks through the wallet and examines the photos of Marguerite, he finds he's fascinated with her and her life, and soon his curiosity about her becomes an obsession.

While fixing up their summer cottage, Michel and his family run into a man who claims to have gone to high school with Michel.

Diego is one of the chiefs of the Spanish Communist Party. On his way from Madrid to Paris, he is arrested at the border for an ID check but manages to get free. When he arrives in Paris, he starts searching for one of his comrades to prevent him from going to Madrid where he could be arrested.