This is one of Hammond Innes' traditional, resolute, driven and intermittently exciting (there are many archaeological explanations of apparently serious derivation to slow you up) story of a paleontologist's lifetime search to prove that modern man came from Africa. In the process it entails some very literal skull duggery. Peter Van der Voort had always been solitary and difficult toward his adopted (natural, it will be revealed) son Paul who dislikes him. Paul has had an uncertain and shady record as a seaman when he initially appears here in Amsterdam to learn that his father has disappeared. This then is his search for his father in Levkas and around the Aegean with some new as well as old bones of contention surfacing all along the way: Paul's acute ill-will against his father; the appropriation of the old man's work by others; and his belief that homo sapiens is decelerating in reverse toward his initial killer instruct. All of it is no more unexpected than the following.