Hekata

From publisher blurb:

Once a rich and mighty empire, Hekata was brought to ruin by the pride and fear of its mightiest ruler. Had it not succumbed to corruption, it might have gone on to conquer the entire continent. But that was not its fate. Cursed by the gods and shunned by the living, Hekata is now a realm of death and damnation, a place where the wise do not tread. This supplement expands on material in the Hellfrost: Land of Fire supplement.

This supplement explores the nature of the Liche-Priest, expands the cult of Tammuz, details 9 fiendish locations and 5 major undead NPCs, introduces 3 new minor deities, and adds 3 new hazards and a system for creating mummies with a wide range of special abilities, plus much more!