A businessman was stabbed during a round of golf. It is his daughter who discovers his corpse, one Sunday morning. The young woman is suspected by investigators because the day before, she had had a heated argument with her father, who accused her of frequenting a trendy nightclub, known to be the hub of drug trafficking. But Revel and Mélanie soon have another suspect, a certain Antoine Copeau, who is none other than Mélanie's former partner when she worked at Stups. Under a false identity, Antoine Copeau became the manager of the box as part of an undercover operation ...

A young architecture student is murdered in the hall of the Gare de l'Est. The investigation of Revel and Melanie Rousseau tells them that he had been selected among the ten finalists in a large architectural project for La Défense. The favorite of the contest is now Xavier Michel Corbin, a famous architect who seemed to exert a strange fascination for the young man who was murdered.

A deputy mayor of Paris was killed in his car, one evening when he was driving home a young social worker with whom he had just spent the evening. Is this a crime of passion or a political assassination? Revel and Rousseau wonder about the real motive of the killer. But soon, they understand that it is in reality the social worker who was targeted. The murder of the politician would only be a smokescreen intended to blur the tracks and to keep investigators away from a gifted 10-year-old boy, perhaps at the heart of this bloody affair ...