Odbald, former head of Britain's biggest police force, has been sacked by the Home Secretary. Having returned to his home county of Dorset he is unable to resist becoming involved in the investigation into a brutal double murder in the Purbeck hills. Soon, however, he is at odds with the police's official lines of enquiry. Having rekindled a friendship with an eccentric, disfigured but brilliant friend, Sandra, he follows his own instincts. It brings him face-to-face with an appalling serial killer he had locked up decades before and the conclusion of that ghastly case, and causes him to unravel the mystery of a dreadful shipwreck in 1830.