Marianne investigates the death of Amandine Laroque, who died after falling into the sea from the top of a rocky eminence. Is it a suicide or a murder? She worked in a detox center for addicts. The employees and patients of the establishment are immediately suspected...

Marianne and Zacharie learn to live together on a daily basis, and thwart the suspicion of Commissioner Franco. Soon, Judge Vauban was called to the scene of a fire breaking out near the creeks. On site, she is introduced to Commander Lamarre, head of rescue operations, who seems very close to Captain Pastor. Arnaud Viguier, a firefighter who responded to a campsite surrounded by flames, was found dead on site. But his body was badly beaten... A letter found in the deceased's belongings calls into question the integrity of one of his colleagues.

Pastor and Vauban are dispatched to the scene of a new crime. An actor portraying an undead in an escape game was killed by participants: the fake revolver had been replaced without their knowledge by a real weapon. On site, the pair of investigators found a lost earring. They also soon uncover troubled actions on the part of the manager. Meanwhile, the situation deteriorates in court, and Marianne has difficulty juggling her very busy job and her new role as foster family for young Zacharie.