Detective Sergeant Guillaume Pelletier heads off for a well-deserved winter vacation at the cottage he rented from his childhood friend François. Just when he thinks he can relax in the countryside, he finds himself immersed in a family tragedy: Céline, François’ ex-wife and mother of his two daughters, is brutally murdered shortly after Pelletier’s arrival. The Cerbère squad’s elite investigator’s vacation quickly turns into a mission: to collaborate with the local police, and in particular with the region’s only female investigator, the calm and friendly Évelyne Dumoulin, in an attempt to identify, from among the suspects in the victim’s entourage, the murderer…