Forensic anthropologist Dr David Hunter is on the remote Hebridean island of Runa to inspect a grisly discovery. Hunter has witnessed death in many guises, but even he is shocked by what he finds: a body almost totally incinerated but for the feet and a single hand. Could it be a textbook case of spontaneous human combustion? The local police are certain it's an accidental death but Hunter is not convinced. Examining the scorched remains, he finds the evidence he feared. It's clear to him that this was no accident, this was murder. But as the small, isolated community considers the enormity of Hunter's findings, a catastrophic storm hits the island. The power goes down, communication with the mainland ceases, and then the killing begins