A mysterious figure signing himself "The Ferret" keeps sending letters to the police, tipping them off about murders that are to be committed around Paris. Among those caught up in the police manhunt is a fraudulent clairvoyant.

Four little girls flee the cold concrete world of the housing project they live in, take refuge every evening in a house on an island in the middle of the Marne River. It is secret hideaway that no one should trespass. Unfortunately a big girl reveals everything to the schoolmistress and scandal breaks out. But it is Sophie, the youngest of the group, who gets suspected by her..."friends".

Louis saves a five-year-old girl, Monique, who wants to throw herself into the river. He consoles her, takes her home and nurses her back to health. Thanks to Monique, the old man regains his zest for life. Monique tells him that she has misplaced her mother's purse and is afraid to go home. Louis takes her back and continues on his way.

These two friendly delivery boys from a Parisian department store not only take their job to heart as much as possible, but also consider themselves responsible for the happiness of the customers they have to deliver to. This leads them successively to help, at the cost of incredible acrobatics, a young couple celebrating the first anniversary of their marriage, to mingle with the clientele of a rather disquieting doctor, to almost perish in an ambush that was of course not intended for them, and to avoid a domestic quarrel.

Laurent, a young playboy, lives off his charms, maintained by wealthy women of the world. He becomes the lover of Sonia, a young woman painter, a lover at heart of course. But Sonia has a provincial friend, Clotilde. One day, Clotilde pays Bona a visit. As she has just come into a large inheritance, Laurent courts her and marries her. The young couple embark on a misguided life of easy pleasures and questionable company. Clotilde's nerves crack at this game. Among Laurent's acquaintances, François, a doctor, treats her in his clinic: sleep cure, rest, etc. Meanwhile, Laurent distracts himself with other women. But Clotilde, convalescing, refuses to resume life together. Laurent turns to his former mistress, Sonia.

A medical doctor gets into trouble when one of his patients turns out have been involved in espionage (maybe).

Julietta Valendor is in love with lawyer André Landrecourt. He is unaware of her feelings. He puts her up one day when he has his fiancée, Rosie, staying with him... Based on a novel of Louise de Vilmorin.