From the introduction:
Many years ago, in the duchy of Gersot, a wizard was exiled by the duke for what were documented as "blatant acts of cruelty and evil". Exactly what these acts were was not recorded although the peasants who farmed the Duke's lands believed it involved demon worship. Filantis, the wizard, swore an oath that he would return one day to take out his vengeance on the Gersot family for the shame inflicted upon him. More than 150 years have passed since that time and the story of Filantis has passed into local legend. There are even some who question the truth of the story, at least that is, until now.
For characters of 6th - 10th level. Usually distributed as a ZIP archive containing the adventure and two image files (maps).