Opale Thalasso, directed by Justine Reynal, has relaunched its activity by teaming up with a popular nutritionist, Marc de Vilde. But one morning, Célia, a 30-year-old physiotherapist and sister of Justine, is found murdered in the swimming pool of the thalassotherapy centre. The investigation reveals that Célia was in a relationship with a former drug addict suspected of criminal activities. Would he be guilty? The investigation begins against a backdrop of romantic rivalries and family tensions.
