The third book in the series, a sequel to Uglies and Pretties.
It’s a solid book, but the flashes of brilliance are harder to find this go. It’s probably because Tally’s “natural” persona is so subjugated at the beginning of the book– and partially because the Specials are annoying twits with a huge chip on their shoulder. While that makes it easy to root against them (when they’re being idiots), you do have to put up with them… and they wear on you much more quickly than the characters of the first two books.
As far as plot goes it’s a good book, and ends the trilogy with a world dramatically changed by the effects of Tally (and friends) over the trilogy. The world gets more complex in this world, and the depth makes it feel realistic, but the dramatic changes fight that complexity.
In the end, I’m probably being overly critical– it was a good book, a solid end to the trilogy– and I’ll read it after the first two when I reread the series. It might gain surprising depth on the reread.