When Denise Morrow is discovered standing over the body of her husband, a bloody knife between them, Detective Declan Shaw thinks it's an open-and-shut case. But Denise is no ordinary murder suspect. She's a famous true crime author, who knows how killers operate. And how they get away with it. Then, Declan discovers the subject of Denise's next book - the violent murder of a girl called Maggie Marshall. A case that Declan worked on. A case that has haunted him for years. Denise knows much more about Declan than she's letting on, and she might just be the slipperiest suspect he has ever encountered...