A Night In The Lonesome October, by Roger Zelazny. One thing I love about it, though not the only thing, is how slowly it starts. You get narration of the main characters—first-person narration, even—doing strange things very purposefully for a long time before you understand why. It carefully drips out the worldbuilding necessary to even know what the premise is, and so just stating it feels counterproductive, but it's probably going to be an annual Halloween reread for me.

Dreamwidth notes: tags don't appear in the order you typed them (a set, not a list) and so you can't split comments across multiple tags! And yes as deusvulture says you are limited in the number of total tags for your account. Also, your account is set to log the IP address of everyone who comments, and you might want to change that to anonymous posters only?