Here’s all you need to know about this superbly unsettling, impeccably controlled novel from the author of The Remains of the Day: (1) It’s a memory piece about a three-way friendship at a British boarding school at which the total isolation of a ”special” student body from the outside world suggests something unspeakable and sinister lurking at the margins. (2) The book’s irresistible power comes from Kazuo Ishiguro’s matchless ability to expose its dark heart in careful increments, so even reading a longer review could ruin it. (3) Although some of Ishiguro’s signatures are evident — an uncanny ear for the language of a narrator whose own perceptions may not be trustworthy — it’s new, alternate-reality turf for him (think Margaret Atwood’s The Handmaid’s Tale). That’s it. Oh, one more thing: After you read it, give it to a friend. You’ll want to have someone to argue with.