I am giving this one 4 stars, but I might change it to 5 stars. I gotta think about it. 
 I told Mimi this book was "good in a bad way", and this review will be my attempt to explain it. *It might be spoilerish, so if you don't wanna read them...* 
 I also just saw Kristen's status update for this book, and she is like, "Oh no! This book is an emotional roller coaster already and we haven't gotten anywhere yet!" I know exactly how she feels. 
 Let me start with the good 
 1. Whatever else I might say about her, however much I can complain about some aspect of her storytelling, Rachel Vincent has mad world building skills. It is her peculiar strength. She creates these worlds that just stand out from all the worlds in the (urban?) fantasy genre. 
 This time around, she introduces us to a world divided along the lines of Skilled and UnSkilled people. From what I understand, there are 12 skills, among them Binders, who can seal any oath and make it binding, Trackers, who can track people by name or through blood, Seers (self-explanatory), Travelers, who can travel anywhere through shadows..... and I don't think she mentioned about the other 8. Yes - pure awesomeness. I want to know more about a world like that, don't you? 
 2. Her other skill is engaging the reader. I am completely focused when I pick up one of her books. I don't skim pages, And I am not impatient to get to the end (sure, I peek sometimes, but I always go back and patiently read from where I was straight through till the end). 
 Then the bad (or it's still more good, depending on how you look at it). 
 1. Her characters often make me violent - I want to slap some sense into them half the time. When I don't want to kill them, I'm rooting for them. 
 Olivia, Anne, Kori, and Noelle were four childhood friends fooling around who managed to bind themselves with an oath to help each other no matter what. Unbeknownst to them, they were all skilled. Anyway, Liv is a very powerful bloodhound - she can track anyone so long as she has a whiff off their blood. Anne invokes the oath when she sends Liv on a mission to track and kill her husband's murderer. Which brings me to the first person I want to smack to high heaven and beyond: Anne. Stupid. Selfish. Despicable. How in the world do you force someone into danger because of revenge for your dead husband? Emphasis on dead. If that thug had been slightly more skilled, Liv would be dead, and there would be no story. Your dead husband is not worth more than your living friend's life or your petty desire for revenge. Simple as that. Endangering Liv to track your missing daughter is understandable, but not this. Never this. Anyway. I never liked Anne, not even when she was doing her 'protective, loving mother' outbursts - it just rang hollow and selfish to me. I don't like her. 
 Then Liv. A prophecy that she and Cam would be the death of each other prompts her to leave him without a word. No explanation no nothing. WTH? That is not noble, or remotely okay. It is an incredibly selfish thing to do is what it is! Why would you do that to someone you claim you love? Oy. 
 Then Cam. the girl you loved and was going to ask to marry you ups and leaves without a word, so what do you do? Sleep with Anne, her best friend. No, he couldn't just get stupendously drunk or get into a fight. Caramba. Now you see why I say this book is good in a bad way? 
 The novel is told from alternating 1st person POV of Cam and Liv, and the world that is revealed through their eyes as they fight to track Anne's daughter is fascinating. It is also raw and gritty. This is a story about desperate people trying to survive in a harsh and unrelenting world. And you come to see and understand them, you understand the choices they make (except that Anne, yuck!) enough to get past their nonsense to root for them and wish for their HEA. In some respects, the ending was rather poignant (just a fancy word for sad :( ) 
 You can bet you I will be preordering book 2 in this series, Shadow Bound. Book 1 comes highly recommended. This world is one you have to experience for yourself.