Ferdinand Griffon (Jean-Paul Belmondo) is unhappily married and has been recently fired from his job at a TV broadcasting company. After attending a mindless party full of shallow discussions in Paris, he feels a need to escape and decides to run away with ex-girlfriend Marianne Renoir (Anna Karina), leaving his wife and children and bourgeois lifestyle. Following Marianne into her apartment and finding a corpse, Ferdinand soon discovers that Marianne is being chased by Organisation de l'armée secrète gangsters, two of whom they barely escape.