From the front page of the PDF:
A One-Round D&D LIVING GREYHAWK®
Iuz’s Border States Metaregional Adventure
Called upon by the allies in the crusade against the old one, their request will lead you to a rescue mission unlike any other you’ve ever experienced before... An adventure for experienced adventures that have caught the eye of the Old One. For characters levels 11 to 17.
WARNING: This adventure is combat intensive and not for heroes who are afraid to die for their cause. This adventure will run longer than one standard convention slot and should not be run without judge preparation.