For the first half of this book I was convinced I was reading a nailed on five star hit. Unfortunately the second half drifted terribly. It's smart and well thought through, but in the end relies too much on telling rather than showing. There's also a marked lack of drama. Incidents in the novel proceed serenely one after another, with no sense of jeopardy or any feeling that the outcome could go another way. Almost a great book, but only almost.