A man is making a crude leather mask with an iron spike fixed in the middle of the forehead. It is a "death mask," once used by Icelandic farmers to slaughter calves, and he has revenge in mind. Meanwhile, a school reunion has left Inspector Erlendur's colleague Sigurdur Óli unhappy with life in the police force. And when a favor to a friend goes wrong and a woman dies before his eyes, Óli has a murder investigation on his hands.