From the back cover:
The Lost Tombs, Volume 3
The Doomgrinder, a mysterious stone windmill many leagues east of the City of Greyhawk, has for centuries been a source of rumors, frustration and fear. The rumors say that vast treasures are stored inside—all cursed. The frustration belongs to hundreds of adventurers who over the years have attempted to enter the windmill and failed. The fear is felt by those who believe the world will end when the stone sails of the Doomgrinder turn again. In the City of Greyhawk, powerful spellcasters read bad omens for the future, and the Doomgrinder is part of them. Some see no future at all, good or bad.
In this GREYHAWK® adventure, a group of brave heroes may finally learn the truth about the Doomgrinder. Designed for characters of level 4 through 8 but adaptable to any level, the adventure can be played on its own or as the climax to the Lost Tombs adventure series. It also offers countless opportunities for spin-off adventures, potentially providing the foundation for entirely new campaign directions, and months of exciting game sessions.