'An investigation consists of a mass of voices, the sort you can hear, and the sort you can't. You have to listen to the soundless voices, Malin. That's where the truth is hidden.' Early one morning in the coldest winter in Swedish memory, police detective Malin Fors is called away from the warm flat she shares with her teenage daughter. The naked body of a man has been found hanging from a tree on the deserted, frozen plain outside the town of Linkoping. From the outset Malin is confronted with a host of unanswered questions: Who is the dead man? How did he end up in a tree? And where did the strange wounds on his body come from? Malin and her team must search for the truth in a community that seems determined to keep its secrets, and follow in the frigid wake of a killer to the darkest corners of the human heart.