While investigating rumors of a dangerous blue dragon wreaking havoc in the deep desert, the heroes tumble under the sands into the magically sealed dome of an ancient palace. The temporarily weakened dome reseals above them, and they are left to explore the golden palace of Zahadran, once seat of power for the legendary Caliph Ardishir the Magnificent. But the dome is weak because it has been assaulted by the mythical storm demon Azi Dahaka and his trapped minions, evil creatures that were sealed under the magical dome to keep them from ravaging an unsuspecting world.