Overall, I really enjoyed this last book of the series. Excellent plotting, strong finish. 
 I won't get into spoilers, but I found a few parts of the resolution unsatisfying, mainly because they didn't get much attention. I'm sure some disappointment is intended, but it just felt unbalanced given how much time was spent dealing with them (read: agonizing at great length over them) throughout the rest of the story. 
 I will add that they'd have a heck of a time making a movie out of this one, especially targeted at a YA audience.