Mathias Pascal, saddled with a stupid wife and a nagging mother-in-law, leaves home and is extremely lucky at several gambling resorts. He returns home and discovers that a drowned man, fished out of the river, bears an uncanny likeness to him and is being buried by his family as him. This, to him, is a pleasant turn of events and he goes to Rome, where he falls in love with Louise Paleari. Count Papiano, a jealous suitor of Louise's, threatens him with arrest unless he produces credentials to prove his identity.

On the night of his marriage, a young bourgeois man runs over a cyclist. He believes he is dead and hides the body. However, a mysterious character will later appear in his life.

An actor argues with his wife and she decides to leave. The day after learning of the mysterious death of his wife in Viña del Mar, he hires a detective to find the murderer.

The love affair of an ex-convict with a showgirl, unleashes the jealousy of his older, wealthy and unbalanced wife. A murder plot, staged phoney suicide and other twists and turns follow.

Michel Piccoli plays a police inspector whose best friend is murdered on the orders of gang boss Charles Vanel. The inspector knows full well that Vanel is too crafty and well-connected to ever stand trial for his crime, so he carefully lays a subtle trap for his adversary. Unfortunately, both Piccoli and Vanel are thwarted by a pair of scheming females.