This has all the qualities of a B movie: hokey dialogue, not entirely believable characters, and a science fiction premise where the science doesn't make a whole lot of sense. But, like a B movie, you won't care while you're reading it -- it's just too suspenseful and exciting. This is your classic can't-put-it-down, read-under-the-covers, when's-the-next-one-coming-out thriller.

Margaret Peterson Haddix, author of the popular Shadow Children series, knows a thing or two about suspense, such as how to maintain it without a lot of the usual fighting, battles, and near-death experiences that most authors seem to think are necessary. Of course she uses the usual tricks of the trade: chapter-ending cliffhangers, creepily mysterious events, gradual revelation of dire secrets, and general air of foreboding. But she uses all that in the service of a radically original and intriguing (if still somewhat fuzzy) premise. The cliffhanger ending will have kids panting for the next one.