from the cover:
Three separate adventures for character levels 1-3
The Haunted Stable
The Secret of the Spider Queen
from the Foreword:
This document contains three separate adventures that can each be played in one night; a single session of from 1 to 4 hours. All require that you place them in existing worlds or campaigns, and provide the necessary support information and systems typical of your style. They range in level requirements, and can be used with minor alterations with any fantasy-medieval role playing game/system. Some will need more preparation than others, and you should thoroughly read each before you begin conducting the adventure.
These adventures are usable with old-school games and their corresponding retroclones, for AD&D and simulacra the recommended levels are 1-3, for Original/Basic D&D and clones the recommended levels are 2-4.