Psychologist James Mannigan is granted a series of interviews with the Vynx brothers, four men of unknown origin found naked wandering Dartmoor fifteen years ago who claim they are not human. Housed in the Seahaven Open Facility in a remote part of Scotland, they live unremarkably alongside other guests.
At first, through his questioning and study, James finds nothing he has not encountered before. Until Guardian, one of the brothers, insists on sharing their beliefs on reincarnation. As events unfold and finally reach a violent climax, James finally learns why he has been chosen.