From the introduction:
You never should have left the farm. "Be an adventurer" they said! "Gold, magic, and glory will be yours!" they said. Now those well-wishers, encouragers, panderers, and hangers-on are all gone, left behind in the stinking taverns and warm beds of civilization. You and your companions? You’re deep in a lightless cavern, in over your heads with meager supplies, swords you don't know how to use, and a few flickering torches. You’re not the only ones there either.
There's a monster in the darkness too, a great beast with terrible claws who can mimic the voices and forms of man, dwarf, and elf. A beast whose true form is only revealed in the ever-so-distant light of day. It could be anyone. Hells... it could be you.
Keep your sword close, your torch high, and a wary eye on your companions and maybe you’ll be able to get out of the depths.