Every autumn, farmers in rural Iceland head to the icy heights of the mountains to gather sheep. In a remote valley, a different discovery is made: a corpse, its flesh picked clean by ravens. There's one detail that makes Detective Hildur Rúnarsdóttir suspect murder, and an observation by her Aunt Tinna strengthens her suspicions.

Hildur has crossed paths with this killer before, and what Aunt Tinna remembers may be the key to catching them. What secrets does Hildur's past hide? And can she face them before another person is killed?