Grace Macallan is at breaking point. All around her, events threaten to run out of control - and a new investigation is testing her to the limit. An undercover officer is missing and a woman is washed up, traumatised and barely alive, on the shores of Berwickshire. She has witnessed horror on the dark waters of the North Sea, but survival turns her life from a bad dream into a nightmare. As she untangles the woman's story, Grace is drawn into a cold-blooded criminal world. At its head is Pete Handyside, a notorious gangland boss who will fight hard and dirty to control his brutal empire and keep the money flowing. But a traitor in his midst is intent upon betrayal - a betrayal that triggers an uncontrollable wave of violence. As she hones in on crucial evidence, Grace knows that one wrong move could end in tragedy.