I'll start saying that I liked Willow right from the beginning! This is rare coming from me because I tend to dislike female protagonists that are annoying or whining or simply weak. Fortunately that's not the case with Willow. She's a reliable, independent girl who knows how to fix cars and does psychic readings. As the story unfolds, we also find out that she's not really human: she's a half-angel.On the other side, there's Alex. He's an assassin of angels, the mesmerizing creatures that came to our world to feed on humans for their life force. Alex is serious on his job, lonely and a bit annoying in the beginning, but thankfully he got better later.If you liked at least one of the main characters, then you're lucky, because a good deal of the book is about Willow and Alex. This was good and bad in my opinion. Good because we actually see their characters growing. I loved that they didn't fall ~eternally~ in love with each other at the first five seconds (this is something I abhorr in YA books. Or any book). Both start kind of hating each other, and as the story progresses, they build a sweet relationship. They actually TALK! About stuff!Though it did have a number of cliche moments, it's okay. I thought this was one of the best aspectsof the novel.The bad side was that we didn't get to see the rest of the characters very much! With the story centered in Alex and Willow's journey, we only had a few POVs from Raziel and Jonah scattered, which didn't really help. Even the annoying typical best friend of Willow, Nina, was pratically shoved off the story, along with her family.Speaking of POVs, I didn't get why Willow had to be in first person, while Alex and the others were in third person. What was the point? It felt weird at first, but then I got used to it.Another thing I didn't like was the heavy use of "um" in the dialogues. I know it's a common thing to say when we're actually speaking, but in a book it's... awkward. It just doesn't flow well. And it wasn't even one or two times, it was ALL THE TIME. With all the characters. At some point I started counting how many "um" appeared but I lost track of it.Despite this minor flaws, I really enjoyed the pace and the story. It was a fast read, with a good deal of action, kissing (a lot!) and emotions. I'm really looking forward for the next book, "Angel Fire".