Led to a crime scene by a mysterious video, Māori detective Hana Westerman discovers a man ritualistically hanging in a secret room and a puzzling inward-curving inscription. Delving into the investigation after a second, apparently unrelated death, she uncovers a chilling connection to a historic crime: 160 years before, during the brutal and bloody British colonization of New Zealand, a troop of colonial soldiers unjustly executed a Māori Chief. Hana realizes that the murders are utu --- the Māori tradition of rebalancing for the crime committed eight generations ago. There were six soldiers in the British troop, and since descendants of two of the soldiers have been killed, four more potential murders remain. Hana is thus hunting New Zealand’s first serial killer.