André Laroche, an industrialist, has just passed away. Face to his grave, as he is being buried, Anne de Vierne, the wife of a magistrate, confesses to her son François that Laroche was in fact Lupin and that he is his natural child. But he is not the gentleman thief's only offspring! Lupin had indeed another son by a housemaid, Gérard Dagmar, a dancer, magician and - occasionally - burglar. Which complicates the task of François who, to respect the last wishes of the testator, has gone in search of the treasure of Poldavia. For he keeps finding Gérard on his way and his efforts are constantly thwarted by his half-brother. Will Gérard prevent François from becoming the worthy successor to their father or will the two young men decide to join forces? That is the question.

A mentally disturbed man named Jérémie is scouring the area in search of women he can strangle with his scarf, which is embroidered with an ibis.

Olivier, a young man, falls in love with Marion Renoir, theatre and screen star, to the despair of his fiancée Antonia. The latter goes to find the actress and asks her to invent a ploy to help her win back her lover's heart. The actress gets caught up in the game and ventures into an intrigue where simulation and sincerity are dangerously confused.

Sherlock Coco, famous detective, tries to thwart the machiavellian plans of the trio of shock. Croquignol, Ribouldingue and Filochard must be extra vigilant, but the profit motive is too strong. As a corollary, the famous pink diamond is also of interest to their legendary enemy, Jo Papillon. But always inventive, they will work out multiple scams and tricks to reach their goals.

The Marquis Rodolphe de Sombrueil accidentally runs over a working man with his carriage and helps his widow -- unjustly accused of robbery -- to find her missing daughter.

A confused pair of airport luggage carriers get involved in the disappearance of some suitcases.

The notorious and mysterious criminal Furax steals France's famous monuments, replacing them with replicas.

Housemaid Georgette loves to gossip and this causes major trouble to people around her.