(this is wholly opinion and won't tell you ANYTHING about the plot, really, only my reaction to it) 
 Literally, and very truly, I may cry because this book is over and I have to wait until next year to read more by Rae Carson. Don't get me wrong, this book is complete on its own; there's no cliffhanger which has left me bereft. However, it's been a long time since I wholly fell in love with an author, her characters, her writing style. The three Carson pieces I've read have all earned five stars for me. 
 Also, my opinion is that it's difficult to write effectively in present tense - and, yep! Carson writes skillful present tense.