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.

While Nounours analyzes the images of the victims, Laurène returns to the library to search about ancient Celtic rituals.

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.

In the lake, a bees attack leads to a sinister discovery. Laurène holds Jonas to find out what he knows about the figure in the forest.

Laurène remembers details of her kidnapping while trying to get help for Nounours. Siriani makes a disturbing discovery.

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.

Laurène shortens medical leave to investigate a murder. In a flashback to 57 BC, Roman soldiers suffer a mysterious attack.

The full moon leaves the city bustling. Hermann struggles with ghosts from the past, and Siriani does not miss out on the opportunity to inspect the quarry.

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.

Laurène finds a surreal crime scene, entitled to a piano in the middle of the forest. Cora tries to figure out what the end of Roman was. Garnier investigates Siriani's past.

With the team embezzled and the day of the dead ever closer. Laurène begs for reinforcements. Strangely agitated dogs lead her to a new corpse.

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.

When animal bones begin to appear in Villefranche, Laurène and Bertrand set up a team to search the forest, and the Children of Arduinna prepare their attack.