The call from Mr Wolski disturbs Dale. He understands a father's concern for his missing daughter, but Wolski hovers on the side of obsession. His daughter, Joanna, vanished from Glastonbury almost a month ago. It's the job of Valentine Investigations to find her. It should be easy to find a young woman with an American accent in rural Somerset. But no one has seen her, or heard from her. The more Dale and Milly uncover about Joanna Wolski, the more they worry about her safety. Then Detective Inspector Lauren Kennedy discovers one of her cold cases, and a fresh corpse, are linked to the same meditation group as Dale's missing person. The killer's calling card, a single black diamond, throws up more questions than answers. Does Glastonbury really have a serial killer in its midst? Who will be next? And where is Joanna Wolski?