3.75 official rating 
 This book felt a little different from what I am used to from Holly Black. It wasn't bad by any means, but it is definitely not what I was used to. 
 I really enjoyed this unseen concept of people becoming "cold" before actually becoming a vampire. The concept was confusing at first (you can only become cold if you are bitten by a vampire and you will not become a vampire yourself, until you bite another person). I didn't understand the who bites who and what happens because of it throughout the first half of the book. After finally understanding it, I thought it was a very interesting concept which also happened to be very original. 
 Let's be honest though, I wasn't completely in love with Tana's character. I couldn't figure her out. At the beginning I saw her as a party girl who happened to be in the wrong place at the wrong time. A little further in after learning a little more about her background, I saw her a dark indie chick who continuously rebelled against authority. Then more was introduced and my vision of her changed once again to regular "girl-next door"... or as much as she could be with what was learned about her background. But underneath all the switching personas that were never figured out, Tana makes some really stupid "I don't want to think about the consequences" choices consistently throughout the whole book. Is this supposed to be part of her personality? Because if so, once again, I see her persona changing again. There's nothing wrong with any of this, except that I haven't been able to figure her out - and she's really not all that complex of a character. I felt like a lot of things happened to her - and not so much like she was making meaningful well thought out choices. Most of her decisions were pretty hasty which ended up making me feel like future events happened to her. 
 I did, however, completely love reading the shorter chapters that were told through Gavriel's POV. We don't know much about him either, but I'm a sucker for a "bad boy". He's not even all that "bad" though. Something about the mystery surrounding him, sucked me in and I found myself wishing that those chapters would have remained longer. I would love to see a prequel about Gavriel and all his adventures as a vampire. I didn't see the twist coming at all with him either! I usually go for the hunky blondes, but I could go for dark and mysterious this time around! 
 I liked that the story was told in the near future making reference to places that people know of and are well populated today. It made it seem like this was something that could potentially happen to us a country/world. Parts of the world, however, felt somewhat undeveloped - maybe it was a little more with the plot end of how vampires and "cold" people ended needing to be quarantined. I know it was explained (and maybe this was just the part that I was becoming bored with) but some parts of it just felt a little underdeveloped. 
 My official rating would be a 3.75 because there were some parts that felt really slow. I know there needed to be a little explanation (world building if you want to call it that), but those parts felt slightly unnatural and slow and because of this, the book took me longer to read than it probably should have. Overall, I really enjoyed the concepts behind this book, but there were also things that I could have done without or parts Holly Black should have spent a little more time on. I will still continue to read anything Holly Black puts out, because she has such a unique way to look at the world and tell a story.