First of all, a confession: I bought this book for the cover. It is an awesome artistic hybrid of Where the Wild Things Are and the cover of the non-white version of Catcher in the Rye.
I am not as in love with the book as I am with the cover art, but I thought it was very good. Evans is a very talented writer and the story is interesting and well-researched. I loved the characterization and the vaguely Southern Gothic mood of it.
However, it's not as good as I might have liked. I felt a definite sense of something missing, and I've thought of three possible reasons for it:
Possible reason one: A review compared it to Donna Tartt's The Secret History, which is one of my favorite books of all time. This was not as creepy or as fast-paced as that (or really anything like it), but it was still unsettling and a quick read. (Also, you should probably read The Secret History as soon as possible.)
Possible reason two: I think my skepticism about the main theme (demonic possession) kept me from getting drawn in as much as some reviewers seemed to be. I wanted to be more emotionally involved, but I just wasn't. I couldn't suspend my sense of reality, for one reason or another. So if you are less cynical and clinical than I am, you might not have the desire for more from this book.
Possible reason three: I found the details more interesting than the main thread of the story itself. I want to read further academically into things that were mentioned in passing rather than the main theme of the story.
Also, this book becomes a lot funnier if you picture Tom, Clarissa, and the godfather (the name slips my mind at the moment) as your various eccentric professors. Example: I imagined Tom as this professor I have for philosophy who, two weeks ago, gave a whole hour-long lecture with his fly unzipped. Instant hilarity.