Fiction by Michael Crichton.
The title of this book is misleading, in my opinion, as is first line of the back-of-the book-blurb "From the bestselling author of Jurassic Park, an epic tale of unspeakable horror...."
This is not in the least a tale of horror. I think it's more of an intellectual exercise. What it is: a re-telling of the classic epic poem Beowulf. Yes, really.
It was really interesting and quite an accomplishment, but if you're looking for an epic tale of horror, this ain't it.
Other books I've read recently by this author: A Case of Need, Micro.