Alice K. Turner
Yup, the history of Hell. Only started, so don't have much to say about it, but it is quite interesting. Starts with the idea of Hell, it started back in Sumer about 4000 years ago, of course it was more the Land of the dead, much as what we would associate with the Underworld of Greek and Roman mythology than the idea of demons and fires etc.
Addendum: This is NOT the book to read right before bed. Attempts to read this book were abandoned due to really disturbing dreams.