A woman is murdered in her London mansion and her husband goes missing. The only leads police have are several objects arranged around the woman's body, including a book called How to Process a Murder by Laughton Rees - a book that appears to have helped the killer forensically cleanse the crime scene. Laughton Rees doesn't usually work live cases, but the presence of her book at this scene draws her into the investigation. As the objects found beside the body lead her closer to the victim's identity, a threat to Laughton and her daughter emerges, as well as painful memories of her past. Now, Laughton has to face her darkest fears and help catch a killer.