Jude Shelley, daughter of a prominent cabinet minister, had her whole life ahead of her until she was attacked and left to drown in the Thames. Miraculously, she survived. A year later, her family ask psychologist Alice Quentin to re-examine the case. But then an elderly priest is attacked in Battersea, his body washed up at Westminster Pier. An ancient glass bead is tied to his wrist. The river has always demanded sacrifices, and now it seems a killer believes it's calling out for more. Alice is certain that Jude and her family are hiding something, but unless she can persuade them to share what they know, more victims will drown...