Underground

We share alternative world-views in conversation and correspondence and by reading authors that we disagree with. We can think that a man's fundamental beliefs are completely wrong but find that he is insightful about common experiences. CS Lewis was anti-Darwinian but wrote insightful fiction. He advised fiction writers that they should never state that an experience was frightening but instead should describe the experience in such a way that readers think, "That would be frightening."

Poul Anderson does this in The Day Of Their Return, 20. Perhaps a familiar nightmare scenario is to be somewhere underground in close proximity to a hostile non-human being? Ivar Frederiksen sees foot prints in a mountain tunnel:

"They were the tracks of a being who walked on birdlike claws. Again Ivar stood. Cold gnawed him.

"Should I turn right round and run?

"Where could I run to?" (p. 225)

 

See also SF And Horror. 

The nightmare passages in a novel by William Dexter mentioned in that post involve human characters lost in large extraterrestrial caves where demon-like aliens arrive and depart by teleportation.