In the January 2004 issue of The Magazine of Fantasy and Science Fiction, they ran a story called "Nimitseahpah". In this story, there is a 'darkness' at the bottom of a mine:
Then that thing that all miners dread came to pass. Something big went wrong, and almost all of the 150 men in the tunnels that day were killed. The details of the disaster were sketchy, Jesse said. Whatever happened was so unusual that the whole incident lay cocooned in legend and rumor. The survivors (there were very few) spoke of things no sane person believed. The mine had come to life. Or the miners had pierced the darkness, and it had devoured them in retribution. All the machinery stopped at once - the air compressors, the big water pump, the man skips - and could not be restarted. Men were sucked bodily into the void, seven thousand feet down. Rescue parties disappeared. Not a single body was ever recovered.
Something as cold as a January night seemed to be dragging me through the sand toward the main shaft of the Pahpocket. I stretched out my arms, grabbing... ...It felt exactly as if the ground around the shaft had tilted and risen upward like the sides of a funnel.
There's obviously something down there; that's the whole point of the story. However, is this at the bottom of every mine if you dig deep enough or only at the Pahpocket?