From the front page of the PDF:
A One-Round D&D LIVING GREYHAWK®
Iuz’s Border States Meta-Regional Adventure
Riggby, Patriarch of Boccob, soul was captured by the forces of Iuz, little over a year ago. Many of Riggby allies have attempted to learn of the whereabouts of the soul stone that contains Riggby essence, but alas with little success. However one man, a cleric of Zagyg claims he knows where an answer can be found and unknown backers are willing to send adventurers towards this destination. This adventure is sequel to Iuz 3-05 Obsession and is recommended for characters of levels 7th – 16th.