At the cable car station connecting Avoriaz to Morzine, 75-year-old Barbara Herbier emerges from between the cabins, looking distraught. Cornered by her invisible attacker, Barbara falls over the railing and disappears into the void. This is only the beginning of a series of sudden and deadly incidents that will strike the Herbier family. Claire Garibaldi, a police officer in Lyon, doesn't believe much in legends when she returns to investigate the scene of her childhood.