Arsene Lupin was a well-known French gentleman burglar who was active at the turn of the 20th century. In this routine costume drama and actioner by Edouard Molinaro, Lupin's two sons, François (Jean-Claude Brialy) and Gerard (Jean-Pierre Cassel) decide to go into their father's profession soon after he has been laid to rest, six feet under. Both sons have their own personalities, and though they go into the burglary business together, they have multiple disagreements. One thing they do agree on is that they must put aside their differences in order to rescue some jewels for a gorgeous princess (Françoise Dorleac. Dorleac, the sister of Catherine Deneuve, was tragically killed in a 1967 auto accident.