I have very mixed feelings about this book. On the one hand, I really liked this story, the plot was exciting and suspenseful and the mythology that drove the plot was incredibly intriguing. I enjoyed learning about the watchers and the emmim, the mythology behind their existence was absolutely compelling. It kept me wanting to know more about them and their history. This was a book that I wanted to keep reading, despite its flaws. The action and suspense were enough to keep me fully engaged in the story even when I was annoyed with some of, what I felt to be, the weaker aspects of the book.The scene opened on the heroine attending and assisting with an exorcism. This certainly set the tone for the exciting premise. The demons were strange and otherworldly, and very cleverly written. The exorcisms may have, at times, lacked the feel of authenticity, but they were still fascinating to witness, especially the way main character, Bridget, interacted with the demons. The two priests that were also attending the exorcisms and advising Bridget were such shady characters, I didn't know which one I distrusted more. The byplay between them effectively communicated the tense relationships between themselves and Bridget.Where I sometimes lost patience with Possess was in the dialog and the characters. One of the most important factors in a book, for me, is the way the characters interact with one another. So, when the dialog is weak, or cheesy, or overdone, it takes a lot away from the story itself. In Possess, it was clearly the intention to make Bridget a snarky, angsty teen, which in itself can be tedious to read. The problem I had with this was that any time she was speaking, whether it be internally or in conversation, there was either a flippant remark or a "poor me" whiny pout. I felt like it was completely overdone and decreased my enjoyment of the book.As a main character, I thought Bridget was a whiny, sarcastic, clueless nitwit. I don't understand why the hints were presented so that the reader understood them, but apparently Bridget did not. It made me feel frustrated with her ineffectiveness as the main character. I also hated the way she treated her "friends" The snarky comments about one being fat, lazy, and gay were a bit over the top. Also, the fact that she didn't discourage the other "friend" who obviously had a huge crush on her, instead, she continued to ignore his hurt feelings as she became closer to another guy without ever addressing the issue or even attempting to salvage the friendship. There were many things like this that caused me to dislike Bridget as a main character.I guess I will be one of the very few, it seems, that did not absolutely love Possess. It simply wasn't for me. I find it very difficult to enjoy a book if I do not like the main character. So, for me, I will be rating Possess a three, because while the plot was fast paced and exciting, the fact that I did not like the main character took much away from my overall enjoyment.