Three young men - Jacques, Pierre, and Michel - share an apartment in Paris, and have many girlfriends and parties. Once, during a party, a friend of Jacques' tells him he has a quite compromising package to deliver, and asks him if he can leave it discreetly at their place. Jacques agrees and, as he works as a steward, flies away for a one-month trip in Japan, telling Pierre and Michel about the package. Then, one of Jacques' former girlfriends drops a baby before their door, making Pierre and Michel believing it is the package they are waiting for. Their lives are then completely changed.

In this film that sends up the foibles of filmmaking, a standard crew of actors, stage-hands, director, writers, producers, and others are gathered for the filming of a 45-second automobile commercial. Each role embodies an archetype (the harried director who has a deadline to meet, the Scrooge production manager who has a budget to meet, and the writers who are above these mundane concerns), and these personalities drive the working actors over the edge until they decide to lock them up and do their own thing -- happiness can be just around the corner if you are in the driver's seat. Hopefully, the actors will be able to bow out before the police catch on to the situation.

Stephane (Victor Lanoux) is the mayor of a small village. He is also the manager of the tannery which provides the inhabitants with work. In a fit of anger, he kills his wife (Edith Scob). A judge (Jean Carmet) tries to prove his culpability, but it's not an easy task, because there is a political and social pressure.

A threesome becomes a foursome in this sensitive drama. The tale begins with the relationship between a recently divorced man and woman (from different marriages) and the bisexual they get involved with. At first all three are happy in their new arrangement, but then the divorced fellow suddenly leaves and those remaining in the relationship become quite tense. Fortunately the fellow returns with another, more conventional fellow. Eventually the three persuade him to join them.