When a body is found half-submerged in a molten mud pot in one of Rotorua's famous geothermal wonderlands, forensics expert Alexa Glock spots a way to prolong her stay in New Zealand, which she has been visiting for work. Teeth are her expertise, and the investigation needs her help, as other ways of identifying the body may have... melted away. Joining Detective Inspector Bruce Horne and his team, Alexa discovers that the murder victim, a city councilman, had trespassed on an island sacred to the Maori. The ancient punishment for such a transgression is disaster, demonic possession, or death... and when she visits the island to investigate, the same outcome is promised for her. Alexa doesn't believe in ancient spirits returning to exact revenge, but then another victim turns up dead, and she begins to wonder whether the real threat is something - or someone - much closer to home.