The mysterious silvered words of prophecy on a tapestry of Irish linen just seem part of the Hebridean island charm of Tìr nam Bàn, where Bruno and his friends are taking kids on a school trip for a week's retreat in a rebuilt Old Catholic Nunnery. Despite the uptight Abbess, and Justin's fear of nuns, students and teachers are having a lovely time on what seems to be a simple island paradise. Entranced by the Aurora Borealis, by the beauty of the island, and more in love than ever with his athletic lover, Bruno has much more to think about than the lights appearing to the north-east of the island when they go skinny-dipping in seas that are freezing even in August. When Bruno and Imogen get drunk after accepting an invitation to an Open Evening at a New Age centre of eco-spirituality, his friends can't believe he had a momentary vision of evil in paradise but his unease grows. When an afternoon cycle ride turns into drug-fuelled lovemaking with an old friend, then a morning swim with seals leads him to an encounter with elemental forces beyond his ken, Bruno loses all grip on reality and tensions rise as the others have to shoulder his work. Bruno feels mad, bad and dangerous to know but, unbeknownst to him, someone who has been with him from the beginning of the trip believes his wild story and together they rescue lives that others are selling to the highest bidder - but not without paying a tragically high price.