Two men and a woman live quite happily together in a romantic liaison. The woman is probably wealthy anyway, so the trio doesn't worry much about money. One day they decide to take a trip in their beat-up car, managing the whole affair in their own special, insouciant manner. They are followed by a suspicious policeman who thinks there's something fishy about this group.

Jane Birkin
as Ariane Berg

Richard Leduc
as Bruno

Raymond Bussières
as Le pêcheur (Buster Keaton)

Georges Mansart
as Patrice

Paul Demange
as Le "spécialiste" des jeux de cartes

Hubert Deschamps
as L'homme au restaurant

Marc Dudicourt
as Le mercier

Martine Kelly
as

Isabelle Huppert
as Une fille ramenée à la maison

Serge Gainsbourg
as L'inconnu du lac