The truth about Marion finally comes to the surface. Bertrand gets violent. Lauren and Cora are caught in a dangerous plot.

Siriani questions Bertrand about the disappearance of Marion. Nounours and Camille investigated the death of a man who knew the events of all his neighbors.

An amateur caver emerges traumatised from a labyrinth of subterranean grottos where he says he lost his friend. Laurene tries to unravel fact from fiction in his witness statement before contemplating a perilous descent. At the same time, Cora thinks that the Mayor's daughter has been kidnapped by a mysterious group of activists who are leaving their marks on the walls of Villefranche.

A traditional ritual of a school with mortals, which is producing tension in the city. Cora has visions of an underground network.

A Sabine barless shootout causes a hunt for a band of armed criminals. Cora and Romano spy on trucks that enter the forest each night.

A wife of a hero commits suicide locally. Laurelyne is sure that he is not what he appears to be and investigates on his own.

Laurene comes face to face with a wolf which appears to be guarding a newborn baby hidden in a box. She undertakes to find the baby's parents, followed from afar by the mysterious animal. As everything rapidly becomes complicated, memories from her troubled past resurface.

A young woman is found hung in the forest and Laurène and her team try to solve the case while welcoming the new prosecutor. There's more to solve: the disappearance of the mayor's daughter, and Laurène’s own kidnapping 20 years ago.