Marceau, interviewed by Aurore, claims to have discovered the mask, worn by the sought -after suspect, near a park by the road without knowing that it belonged to Bastien. He claims to have spent the night from Sunday to Monday at his home, alone. A doubt persists, in particular because of its reputation as a joker on social networks and its intrusion suspected at the fun fair recently. However, Damien confirms thanks to clues noted on the scene that Marceau tells the truth about the discovery of the mask. The young man remains in the police sight, until the arrival of Lilou.
The latter spontaneously appears at the police station. She explains that she spent the night concerned with Marceau and asked him to remain silent so as not to arouse the suspicions of her boyfriend. Thanks to this testimony, Marceau is ultimately bleached. Aurore, Georges and Sara then resumed the investigation to find the real culprit. Meanwhile, Ludo goes to the hospital to ask for anxiolytics at Victoire, who refuses without prior consultation. Troubled by his behavior, she wonders about what he really seeks to hide.
Wedding in sight
The tension rises from a gut in nautical jousts: Fred confronts his coach, José, in a spectacular duel. But the party turns into drama when José, projected in the water, does not go up to the surface. Rescuers can only see his death. The autopsy of the facts reveals that a trapped device had been hidden in his shield: by filling with water, he activated a taser, causing the electrocution of the victim. Karim and Aurore make a link with the murder of Hélène Deville, also committed in an animated context. A disturbing element returns to both cases: a small hidden button, left like a signature. The idea of a serial killer takes shape.
Far from these dramas, Jordan finds Judith in the back of Violette. Both spend an accomplice day at the beach. Meanwhile, Violette, without suspecting anything, crosses Marceau with a hut, which openly tries to seduce her. In the evening, Chloé tells Alex her intention to see Michaël in detention. Finally, Martin, with the help of Camille and Maud, is organizing a romantic picnic to ask for Raphaëlle in marriage. She accepts, moved.