When the Paris police's vice squad - on the orders of Police Chief Lépine - begin to clean prostitutes off the city's streets, a man's body is found in the Bois de Boulogne. Inspector Antoine Jouin is entrusted with the investigation.
Guichard falls into the trap when he is lured to Château de Bagatelle by a phone call from Fiersi's son, Julien. And Commissioner Lépine confronts Fondari, the head of the vice squad.