Gunshots resound in the mountains: the valley of Lusagne is preparing to welcome the wolf hunt. While the village is busy preparing for the event, mysterious human bones are found in a cave. William Delapierre, a young man with no family or attachment, was coldly shot in the skull and abandoned in the mountains. Alex Hugo is convinced that the case conceals a mystery more complex than a simple settlement of accounts. The discovery of a wild teenager, lost in the forest, will prove him right. Then begins a long hunt to discover the dreadful truth.