This, I believe, is my favorite book in the series. The characters go through so much, but they all really grow and learn just how much they are willing to go through for one another. 
 I liked the focus of the story being on the Fae. It was interesting to get to visit their "world" (reservation) and see that not everything is as it seems on the outside. We were also given glimpses into what other magics Mercy can penetrate / withstand being a Walker. 
 This is a very emotional book. There are parts that are difficult to read (not because it's boring but because of the subject matter). I don't want to give too much away, but if you're like me you've probably stumbled upon a review that's already talked about the big occurrance in the book. The way the situation is handled reveals a lot about our main (and a couple secondary) characters. We truly get to understand their feelings in this book. Nothing is hidden anymore. This is also a test to how truly strong Mercy is both physically and mentall / emotionally. She will not let what happens to her effect her life. It's a very positive stance. 
 In this book Mercy finally chooses between Adam and Samuel although looking back (this is my 3rd read through), I can't really imagin her picking any differently. I don't think it was any contest as to who she would pick. But this book (with what happens to Mercy) really helps us see just how much she is cared for. Not just by the man she chooses but by everyone in her life. 
 This book kind of ends on a cliff hanger (nothing major), but never fear, if you are coming into this series now then the 4th book is already out and it picks up exactly where the 3rd book ends. With that said, I am off to re-read the 4th book. 
 Side Note: This is also my favorite book cover of the series so far.