Descent into the Underearth

Subtitle: An Unofficial Supplement for InSpectres

From the Introduction:

Descent into the Underearth is intended as both a light hearted take on the speculative fiction novels of the likes of Jules Verne and H.G. Wells, and as a nostalgic nod to the classic dungeon-crawl adventures from the early days of roleplaying games. Journey to the Center of the Earth meets The Vault of the Drow. Did you ever wonder why there was never a good reason for your characters to be crawling around underground (aside from the opportunity to commit murder and mayhem away from prying eyes)? Well now there is. Come join us in an age of scientific discovery, when the glorification of personal reputation took precedent over scientific ethics!