Nor Crystal Falls (2003)

A One-Round Living Greyhawk Tuflik, Fals, and Velverdyva Trade Route Meta-Regional Adventure

From the introduction:

Local talk along the Velverdyva Trade Route speaks of adventure with Lords Burne and Rufus. The Lords have called for worthy adventures to interview for an expedition. No clues as to where or what the expedition is to be. Heroes that have dried the water from behind their ears are encouraged to seek an interview with Lords Burne and Rufus at Doomwatch Keep.

An introductory adventure to the Tuflik, Fals and Velverdyva Trade Route Metaregional Campaign for characters from level 3 to 14.

Part One of the Three is the Evilest Number Series