Margot Rimel was locked in a shark cage eight meters deep, until she died. Who could have been so cruel to this young oceanographer? By diving into the depths of the ocean, Saint-Barth discovers that her murder is linked to a pearl of inestimable value, an object of desire and the bearer of a terrible curse... On the private side, the past also comes to the surface and the revelations that Saint-Barth will have to face will be breathtaking...

Saint-Barth is reeling from recent revelations about his past when he is called to a new crime scene. Célia Gomez, a young nurse, was found dead in her convertible, a syringe stuck in her heart… The Saint-Barteam discovers that she was sleeping in the back room of a nightclub and that she was using her nursing skills for not very legal purposes. To shed light on this new mystery, Saint-Barth will have to investigate the world of partying. A journey to the end of the night from which he will not emerge unscathed… Fortunately, his old friend Auguste is there!

Saint-Barth and Commissioner Baccara are attending a reception at the prefect's when a parachutist falls from the sky in the middle of the buffet! However, Matteo Coloni was dead before his landing. But who could have killed this freefall instructor in mid-flight? By getting under the victim's parachute, Saint-Barth discovers that behind his leisure activity, Matteo was not only landing thrill seekers on the island... Saint-Barth and Deborah are getting closer... Will Avril be as insensitive as she thought?