In Falkenberg, Sweden, the mutilated body of talented young jewellery designer Linnea Blix is found in a snow-swept marina. In Hampstead Heath, London, the body of a young boy is discovered with similar wounds to Linnea's. Buchenwald Concentration Camp, 1944. In the midst of the hell of the Holocaust, Erich Hebner will do anything to see himself as a human again. Are the two murders the work of a serial killer, and how are they connected to shocking events at Buchenwald? Emily Roy, a profiler on loan to Scotland Yard from the Canadian Royal Mounted Police, joins up with Linnea's friend, French true-crime writer Alexis Castells, to investigate the puzzling case. They travel between Sweden and London, and then deep into the past, as a startling and terrifying connection comes to light.