From the publishers blurb:
A local tale whispers of a strange sorcerer who has dwelt in the cliffs and crags for centuries. During that time savage lightning has illumined the skies and valleys, seemingly at the bidding of this enigmatic figure. More recently there have been even more bizarre stories. Horses stolen by blue-skinned men for unseemly purposes — disrupting trade and traumatising travellers. You have heard these disturbing stories, whether they be founded in truth or fiction. But one question remains: will you brave the journey to the crags?
The Cliff-Lair of Heeter is a mini-adventure for 4-10 characters of 1st-3rd levels. It is compatible with the 1974 edition of the world's most popular fantasy role-playing game, or a similar retroclone.