Jonah has always known he was adopted, so when he gets the first letter in the mail--you are one of the missing--he's able to tell himself it's just a prank. But when his friend Chip gets one, too, it's less funny. Especially since Chip didn't know that he, too, was adopted. As they both start asking questions, they learn that the circumstances of their adoptions were even more mysterious than they'd ever dreamed... 
 Intriguing and engrossing, the kind of book you fight off sleep for. The denouement is a little muddled into an action sequence with bits of exposition sprinkled through, but it had to end somewhere, I guess. I'm not as blown away by it as I was the first book of her Shadow Children series, and this is more obviously setting up sequels, but I'll keep reading it for a while.