Despite many years living in South Devon, DI Wesley Peterson has never visited the tiny island of St Rumon's. That is until erosion from a storm reveals three bodies buried outside the local churchyard.

Two are ancient skeletons, but one is far more recent, and Wesley realises he has uncovered a case of murder. But whose remains are they? And who killed them? The island has only a small number of inhabitants. Yet one resident keeps cropping up in Wesley's investigation: the author and self-styled academic, Quentin Search.

Meanwhile Wesley's friend, archaeologist Neil Watson, becomes fascinated by the remains of the island's old priory. His discovery of a journal, written by a sixteenth century cleric, reveals an eerie tale of strange rituals and disturbing deaths. As Wesley begins to wonder whether the past might be repeating itself, another murder occurs... There is a calculated killer on the island - one whose grip is as deadly as the rising tide.