A One-Round Living Greyhawk Theocracy of the Pale Regional Adventure
From the introduction:
From the city of Calbut, in the Stonelands of the Theocracy of the Pale, the call has gone forth for volunteers to take on a deadly mission; a mission that could spell the success or failure for the city and maybe the Theocracy itself. This call is for all adventurers as well as those in the Pale Militia, Pholtan Knights Valorous, and the combat arm of the Church of the One True Path.
This battle is for [characters level] 14 - 16.