This has a rather convoluted plot, but it would still be clear as glass from the point of view of the heroine, Eve, if she weren't so painfully stupid. A graduate student researching the history of witchcraft, she's clearly capable of intelligence but is absolutely bereft of common sense. I'd say her gullibility is down to drugs, but even so! It puts me in mind of horror stories about haunted houses, where the protagonists should clearly get the hell out but instead keep wittering on about problems with the plumbing and so forth.

It also makes me think of mechanisms of knowledge in horror stories: how people decide what and who to believe. In many cases, academia and a sense of rationalism is far less helpful than more lowbrow sorts of knowledge - although there are exceptions, as in Kostova's The Historian, which is so far above this in every respect. There might be a paper in there somewhere...