I'm not sure of this rating as I've just finished the book. I struggled reading this but I feel that was me more than the book. There are holes in the background of the story and I have questions. But they don't take away from the plot. I thoroughly enjoyed this when I did pick it up. I almost wish this wasn't a stand alone because I'd love more story in this world of demons, sentient books and magic. But knowing how rare and difficult it is to create a unique fantasy and keep it to one novel, and under 500 pages, I am well satisfied.