Avernum is a nation underground. Its pale people live in endless miles of tunnels, pits, and gigantic caverns. Some come to Avernum to work the mines. Others come to hunt monsters for their treasure. And some risk life in the underworld because it is the only place where a person can be free from the total rule of the Empire.
But life in Avernum just became a lot more dangerous. All at once, everything has gone wrong. The savages and dark creatures of the lower tunnels, once beaten into submission, have returned. Gigantic beasts, shielded by powerful magic, have taken up residence in the cities, wandering and killing at random. And normally peaceful citizens have been afflicted by a strange, overwhelming paranoia, making even regular townsfolk unpredictable and dangerous.