In the Swedish hamlet of Hesjövallen, January 1960 nineteen people have been massacred. The only clue is a red ribbon found at the scene. Judge Birgitta Roslin's Andrén grandparents, and an Andrén family from Nevada are among the victims. She then discovers the nineteenth-century diary of an Andrén ancestor, a gang master on the American transcontinental railway, that describes brutal treatment of Chinese slave workers.

It is the first thaw of spring and the body of a young woman surfaces in the River Thorne in the far north of Sweden. Rebecka Martinsson is working as a prosecutor in nearby Karuna. Her sleep has been disturbed by haunting visions of a shadowy, accusing figure. Could the body belong to the ghost in her dreams? And where is the dead girl's boyfriend? Joining forces once again with Police Inspectors Anna-Maria Mella, Rebecka is drawn into an investigation...

Chief Inspector Van Veeteren is called in to help the local police find a suspected serial killer who seems to choose his victims at random, but the case becomes more personal when a colleague is taken by the murderer, leading Veteren and the police on a chase to find their friend before it is too late.

"In murder investigations, it pays to keep things simple: motive, method, opportunity. But the case in front of Detective Fabian Risk is a nightmare. A killer who strikes out of nowhere. No apparent motive. No consistent method. Victims are tortured, strangled, burned, dismembered -- each grisly killing carried out with savage precision, as if following the rules of a hellish game. Fear and chaos have spread through the seaside town of Helsingborg....