Jude Shelley, the daughter of a prominent cabinet minister, was assaulted and left for dead in the river Thames. Her attacker was never caught. A year later, forensic psychologist Alice Quentin is asked to re-examine the case.

Then another body is found: an elderly priest, washed up at Westminster Pier. An ancient glass bead is tied to his wrist.

Alice is certain that the Shelleys are hiding something - and that there will be more victims unless she can persuade them to share what they know.

The Thames has always been a site of violent sacrifice. And Alice is about to learn that some people still believe in its power…