A One-Round Living Greyhawk Veluna Regional Adventure
From the introduction:
The Rings of Austor are gone. The Diocese of Whitehale has been invaded, Castle Sepher and Whitehale City overrun. An ominous black cloud blankets the land, blotting out the sun while orcs, undead, and devils run amok. Armies muster in Mitrik against this unnatural enemy. War has come to the Vale of Luna, and the Archclericy needs the strength of heroes.
The conclusion to the Rings series and the Paranoia and Deceit Series.
A battle adventure for heroic volunteers [of levels] 2 - 16.