It's the end of the season, the vacationers are leaving, the snow is melting - and the corpse of a murdered woman is revealed in an intriguing and macabre scene. The Swiss captain Sterenn Peiry is in charge of the case, soon supported by the French investigator Lyes Bouaouni who reveals to her that a body was found in a similar state on the other side of the border. As the mystery deepens, the investigator discovers that her son accidentally killed his girlfriend in the car. Her life changes: how far will she go to protect her son?