In the Alps, a caravan burns, enclosing a seasonal worker in its flames. Emilie Karras, a young gendarme from Lyon, originally from Les Clairies, leads the investigation, forced to collaborate with Major Servoz, a disillusioned local gendarme.

Thirty six thousand years ago, in the Ardèche river gorge, when an animal was painted, it was hunted. When it is again time to go hunting and painting, Gwel is appointed head of the group of hunters while Karou the painter and his apprentice Lani set off to paint the walls of the great cavern. But they hadn't counted on meeting a cave lion.