Marnie Bruce has hyperthymesia; she can remember everything she has ever seen. Everything except from one fateful night when she was eleven; she woke up in an isolated cottage with a head injury and her mother gone. Twenty years later Marnie heads back to Scotland seeking answers to what happened, but in the small town of Galloway, her mother's disappearance still burns in the air and Marnie's return looks set to tear open old wounds for many of the locals. For DI Marjory Fleming the disappearance of Karen Bruce is a case she would prefer not to re-open but the ripple effect of Marnie's return makes it clear this is one mystery that must be solved. As Fleming unravels the secrets of the past, she realises Marnie's life is inextricably, terribly linked to a monstrous crime decades ago. Can Fleming fit the puzzle together before it's too late? And will the truth be one Marnie wants to remember?