Inspired by the adventures of Arsène Lupin, gentleman thief Assane Diop sets out to avenge his father for an injustice inflicted by a wealthy family.

The head of a famous artist with a sordid past is found in the catacombs in Paris. In his studio, Commissaire Rousseau and the young profiler Mariella De Luca discover a second decapitated body, his wife's. The mystery deepens when another head is found a few days later.