I took the skull from its evidence bag and gently set it on the stainless steel table. 'Tell me who you are...' As a favour to a colleague, Dr David Hunter is on the remote Hebridean island of Runa to inspect a grisly discovery. He's familiar with death in all its guises but is shocked by what he finds: a body, incinerated but for the feet and a single hand. It appears to 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 evidence that this was no accident; this was murder. And as the isolated community considers the enormity of Hunter's findings, a catastrophic storm hits the island. The power goes down, communication with the outside world ceases... and the killing begins in earnest.