A One-Round Living Greyhawk Keoland Regional Adventure
From the introduction:
Disturbing rumors of missing persons and strange figures moving around at night have been filtering out of the Duchy of Dorlin. A rain of evil begins to fall within the borders of Keoland. The PCs must stand against the trickle, or it will rain, rain hard, and flood so that all they hold dear will be washed away.
A Keoland Regional adventure for APLs 4-12, and Part Four of the Crowning Glory Series.