Laurène cuts her sick leave short to investigate the murder of a quarry worker. In flashbacks to 57 B.C., a Roman expedition takes a harrowing turn.
While Teddy Bear combs through the latest victim's Super 8 footage, Laurène returns to the library to research ancient Celtic rituals.
A bizarre bee attack leads to a grisly discovery at a pond. Laurène takes Jonas into custody to find out what he knows about the figure in the forest.
As the full moon sends the town into a frenzy, Hermann grapples with ghosts from his past, and Siriani seizes a chance to inspect the quarry.
Laurène stumbles on a surreal crime scene near a piano in the forest. Cora searches for clues to Roman's fate. Garnier digs up info on Siriani's past.
As Laurène desperately tries to escape the ravine and get help for Teddy Bear, memories of her kidnapping surface. Siriani makes a troubling discovery.
With the squad hobbled and the Celtic day of the dead looming, Laurène begs a commander for reinforcements. Dogs lead the way to another body.
As animal bones pop up around Villefranche, Laurène and Bertrand assemble a team to scour the woods, and the Children of Arduinna prepare their attack.
As Maj. Laurène Weiss and her team work to solve the murder of a local nurse, a new prosecutor arrives to investigate Villefranche's high crime rate.
Laurène finds a wolf guarding a newborn baby in the woods. But just as the team tracks down the child's family, the case takes another maddening turn.
After a terrifying ordeal in a nearby cave, a man begs for help for his trapped girlfriend. But his story doesn't quite add up.
A time-honored high school ritual takes a deadly turn, stoking tensions in the town. Meanwhile, Cora gets a glimpse of an underground network.
A shootout at Sabine's bar triggers a hunt for a band of armed criminals. Cora and Roman spy on trucks entering the forest under cover of night.
When a local hero's wife commits suicide, Laurène becomes convinced the man isn't what he seems -- and goes rogue to uncover the truth.
While Siriani grills Bertrand about Marion's disappearance, Teddy Bear and Camille look into the death of a man who knew all his neighbors' secrets.
As the truth about Marion finally emerges, Bertrand turns violent, and Laurène and Cora become caught in a dangerous web.