Forest of the Chartreuse massif. A group of lumberjacks working on a job come across the body of a man suspended in the air by a rope system, as if it were a sort of disarticulated puppet. In charge of the investigation, Justine Verard is forced to collaborate with Mehdi Djaoud, whom she holds responsible for the death of her husband, himself a detective, during a mission that went wrong five years earlier. Despite this tragic past, the two agents will have to join forces to solve this first mur...