"The Injudicious Prayers of Pombo the Idolater" by Lord Dunsany

gloaming: twilight; dusk

"fate of Slith" - from the previous story in this playlist: "Probable Adventure of the Three Literary Men". If you missed it, be sure to look for it!

I was starting to wonder if there was going to be any internal consistency in this book, and lo, here we have an answer.

The picture used is an illustration by Sidney Sime in the 1912 edition of "The Book of Wonder".

To follow along: https://www.gutenberg.org/files/7477/7477-h/7477-h.htm#THE_INJUDICIOUS_PRAYERS_OF_POMBO_THE_IDOLATER