Explanatory Excerpts and Notes
Regarding
A Night In The Lonesome October, copyright Roger Zelazney, 1993.
Used in loving memorial, but without permission.

Preamble: a conversation between the two main characters, a cat named Graymalk and a dog-like entity named Snuff:

Gray: "How many times in a century does the Full Moon rise on Halloween-three, four?"
"It varies," I responded. "It's more interesting to ask, on how many of those occasions do the appropriate people gather to try for an opening or hold for a closing?"

 

Main premise of the story:

When a full moon occurs on Halloween, occult powers are heightened to the point where extraordinary things may happen. On certain of these occasions, an attempt will be made to allow back into the world that which was banished from it. As most do not hold this to be a good thing, the attempts are opposed... the process of this struggle is known as 'The Game'.