A storm ravaging southern England causes the collapse of the rubbish tip at Abbotsfell in the Chilterns. John Thorneycroft, a forensic psychiatrist on holiday with Chief Detective Inspector, Fergus Lowry, discovers in the landslip a human skull and with it a plaster cast of a much earlier hominid skull, possibly man's immediate predecessor. Are these the remains of a murder victim, and how are they linked to the fossil cast? Now, Thorneycroft's skills are put to work. From the old bones buried an aeon ago and the lies and secrets of the recent past, he must establish the motive and method of a murderer.