Charles Williams was a contemporary of C.S. Lewis and J.R.R. Tolkien, so All Hallows’ Eve is a cerebral kind of horror that you won’t be able to get through in one weekend – but you could finish it in a week and get to the end before Halloween. (The link to my original post will open in a new tab.)
This is one of the creepiest horror stories I’ve ever read – and I don’t mean in a delicious Merrily Watkins way; it carries themes that are dank and unpleasant, albeit without gore.
There is a thread of antisemitism running through the book – very surprising to historically challenged me, since it was written in the 1940s by a British author and is set in WWII England. This has has eliminated any respect I might have developed for the author, but I believe that confronting and calling out bigotry in literature enhances our skills to do so in real life.
You may be able to find All Hallows’ Eve in your library. There is also a Kindle version available for less than $5.