@l1ama: Hmm. Iain Banks is kind of a shameful gap in my SF reading, I should get into the Culture series. Anyway,The Gone-Away World prominently features the twist Abby mentioned too. But who knows--it feels like a very common plot element, especially in sci-fi/fantasy.
@ybbaaabby: The book you were talking about may be The Gone-Away World by Nick Harkaway. If so, your take is absolutely the correct one. It is long and not good.
ShadyPingu's comments