Babel's Basement in Bloomington, MN

First published as "The Drune" by Swift Publishers in 1999. The direct descendent of a carnivorous dinosaur has returned to claim the Earth. Commander Pyg sets up her base in the ancient subterranean Ossiane Empire. Nothing can stop her exterminating the human race apart from an eccentric geologist, sceptical science master, and a few surviving Ossianes. And none of them know about the comet on collision course with the Earth.
Dodo Books