We picked this up as a last minute audio CD set to listen on our Xmas road trip. I had read that this was an extremely popular, young adult fantasy series and the blue-haired teen heroine sounded like a perfect companion on our journey. I agree with many of the GoodReads reviewers who say that the first half of the book is mesmerizing, and then it sadly veers off into a complicated, dense world of angels fighting demons. We lose track of our great heroine and never quite find our way back to her, which was a sincere disappointment. But it's full of great imagery. Five stars for the first half of the book!