Ferdinand Griffon is an unhappily married man who was recently fired from his job as a TV broadcaster. After attending a party full of meaningless conversations, he feels the urge to escape; and that is exactly what he does—he runs away with his former girlfriend, a babysitter named Marienne Renoir, leaving behind his wife, children, and bourgeois lifestyle.

Upon arriving at Marienne’s apartment, where he finds a corpse, Ferdinand soon discovers that Marienne is being followed by gangsters. Marienne and “Pierrot” (an unwelcome nickname Marienne gives Ferdinand, meaning “sad clown”) embark on an adventure from Paris to the shores of the Mediterranean in a car that belonged to the dead man found in Marienne’s apartment.

From then on, they lead an unusual life, always on the run. They settle on the French Riviera after burning a car full of money and sinking another stolen one into the sea. Their relationship becomes tense; Pierrot starts reading books and keeping a diary, while Marienne grows bored and insists on returning to the city.

In the city, at a nightclub, they encounter one of the pursuers. In the ensuing confusion, Pierrot and Marienne get separated, and the gangsters torture Pierrot to force him to reveal Marienne’s whereabouts. He deceives them, telling them Marienne is at the “Marquis” dance hall. They leave, doubtful but alive.

Pierrot and Marienne reunite, but now Marienne uses Pierrot to get hold of a bag full of money, only to then flee to an island with her real boyfriend named Fred, whom she had previously claimed was her brother.

Betrayed and furious, Pierrot finds Marienne and Fred and kills them both. He takes blue paint and smears it all over his face, then decides to blow himself up by tying sticks of red and yellow dynamite around his head. After lighting the fuse, he has second thoughts and tries to put it out, but because his vision is blocked by the dynamite strapped to his head, he fails and blows himself up in the explosion.