It's a post-nuclear-holocaust world, we think, although the forbidding of all things from before has made it difficult to tell exactly what happened. Some of the children born since the disaster known as The Great White have unusual mental powers. However, the religious sect that is the current law of the land has forbidden all such powers, condemning people who have them to death or banishment to Obernewtyn, a place rumored to do experiments on those banished. Our young heroine, Elspeth Gordie, is unsure about the powers she has, and her process of finding out what she can do also becomes the reader's process. This bogs down occasionally, as when a new power is required, and it's unclear whether Elspeth knows she has this power or is trying something for the first time.
However, her slow unraveling of the secrets of Obernewtyn is paced just right for young mystery readers. And that the book ends while we still don't really understand Elspeth's powers shows that Carmody is self-consciously mysterious, leading us to the next title in a subtle enough way that I avoid my usual next-title annoyance. (We all have little things that drive us nuts!) I've just put Farseekers, the next title in the series, on hold.