Returning from a mountain run, Alex saves Élise from a suicide attempt. Seeking to understand the causes of his gesture, he discovers that the young woman has been the victim of a rape. The crime goes back a week, but Élise has no memory of it because she was drugged and her attacker hit her during a nightclub party where everyone wore masks. Alex convinces her to file a complaint and puts the rural and the criminal on the spot. While Angelo entrusts the young woman to the care of Thérèse, an old friend who helps victims of sexual assault overcome their trauma, Alex conducts his investigation and discovers that a young woman, Ariane Brazac, also present during the evening , has a strangely destructive behavior, a sign that she too would have been attacked. For their part, Dorval and Renart realise that the man who assaulted Élise is the serial rapist they have been tracking for months.