In a Copenhagen park, the body of an elderly woman is discovered, and the case bears a striking resemblance to another unsolved homicide from over a decade ago. Meanwhile, a group of young women are being hunted. Could these acts of violence be related? Detective Carl Mørck of Department Q is asked to solve the case—his seventh, after The Hanging Girl—but it could be his last; failure to meet his superiors' expectations will mean the end of this cold case department. The investigation, however, is not their only concern. Their colleague Rose is still struggling to deal with memories of a brutal crime, and it is up to Carl, Assad, and Gordon to uncover the dark truth at the heart of Rose's childhood before it is too late.