Following the discovery of the lifeless body of a woman bearing an uncanny resemblance to a mermaid, Commandant Jérémy Laubier calls on Morgane Ledantec to help him with his investigation.

Following the discovery of the lifeless body of a woman bearing an uncanny resemblance to a mermaid, Commandant Jérémy Laubier calls on Morgane Ledantec to help him with his investigation. The discovery of a drifting fishing boat with no soul on board makes the investigation even more complex when the mermaid's DNA is found on board. What is the link between this mermaiding enthusiast and the mysteriously missing fisherman? While many think he drowned, Morgane knows he's still alive and that he's the key to all these mysteries. It's this link that Jeremy must discover, and even if he still doesn't believe Morgane's intuitions, he has to admit that she's often ahead of the traditional investigation.—Happy_Evil_Dude