As terror ensues inside the mine, a riot breaks out at the Arcacia lab. Gio desperately attempts to locate the group in the tunnel before it's too late.

Jaro and Gio pair up after her son makes a disturbing discovery in the mines. Roméo is the guest of honor at a tense dinner with Hari and his mother.

Gio's theories create cracks in her marriage. Ida tries to make sense of DNA tests as Jaro and Roméo visit a psychiatric hospital in a state of chaos.

Gio and Ida find common ground as they explore hidden mountain terrain. Jaro and Roméo seek out a recluse who may know the truth about Roxane Vial.

As Ida and Jaro look to old VHS tapes for clues, a suspicious Giovanna visits the Arcacia lab. Trouble brews ahead of the annual festival of Lévionna.

Convinced that her missing dad is in danger, Ida follows his trail to a town in the French Alps. A second disappearance brings an old case to light.