Michel Poiccard, an ex-airline steward turned hoodlum, steals a car and heads to Paris. Discovering a gun in the car's glove department, he uses it to shoot and kill a cop who tries to wave him down. He wants to escape to Italy with his American girlfriend Patricia, but the police are after him, and he is distracted by all the pleasures Paris has to offer.

After escaping his stale, bourgeois marriage, Ferdinand Griffon (Jean-Paul Belmondo), a man on the run, encounters a captivating woman, Marianne (Godard's then-wife, Anna Karina). Striking up an immediate connection, the two begin a freewheeling affair that leads them to the Mediterranean Sea. There's one slight problem, though...