The quest for the mystical aeon orbs leads the heroes to the Vault of the Black Desert, a vast underground cavern where bloodthirsty, fiend-worshipping warriors clash against a necropolis of undead drow elves. In the long-abandoned ruins of a forgotten empire, the heroes uncover an insidious plot to seize control of the cavern and bring devastation and ruin beyond its sandy wastes! The Extinction Curse Adventure Path continues with "Lord of the Black Sands," an adventure for 15th- to 17th-level characters.