In a prehistoric underwater cavern off the coast of Marseilles are the first human engravings known to man. Among them is a crude drawing of a three-fingered hand, which has long puzzled archaeologists. Is it a hunting signal? A mystic sign invoking the spirits? Or is it, as many believe, evidence of ritual amputation in a Shamanistic world?

The one who names himself ‘The Hunter’ apparently believes the latter. Driven by strange voices to kill and mutilate, he severs the body parts of his victims and always signs his horrific crimes with a drawing of a three-fingered hand. The identity of this brutal killer is unfathomable, but Michel de Palma, of the Marseilles murder squad, has never lost a case, and he is not going to start now.

De Palma heads to the University to investigate, but the clique of pre-history professors he encounters are as secretive as the cave-drawing itself. Slowly and alone, de Palma unravels a mystery that dates back to the Ice Age, and he comes closer to discovering the killer’s identity. But the academic community protect their own and de Palma is no longer welcome in their circle…