In Search of the Unknown is a module for the Dungeons & Dragons roleplaying game, designed for use with the Basic Set of rules. It was written by game designer Mike Carr and was first published in 1979 by TSR, Inc. The module details a hidden complex known as the Caverns of Quasqueton

 Reviewers considered it a good quality introduction to the game that was written in the so-called dungeon crawl style, where the primary goal of the players is the exploration of a dangerous labyrinth to battle monsters and obtain treasure.

Front and back cover have small stains and wear. The spine has wear, stress cracks and four tape repairs. Corners are soft. Pages are off white and have a water stain on the back inside cover of the book. See pictures