Bruno's promotion to Chief of Police of the valley of the Vézère river has not changed his first loyalty to the town of St Denis. His main wish is to keep the local people safe and his town free from crime. But crime has a habit of finding its way to him. For thirty years, Bruno's boss, J-J, has been obsessed with his first, unsolved case, and Bruno knows that it continues to haunt him. A young male body was found in the woods near St Denis and never identified.
J-J keeps the skull as a reminder and calls him "Oscar". Visiting the famous pre-history museum in nearby Les Eyzies, Bruno sees some life-like heads expertly reconstructed from ancient skulls. He suggests performing a similar reconstruction on Oscar as a first step towards identifying him. And so the search for Oscar's killer begins again in earnest.
