While serving out a life-debt, Red Sonja uncovers a sinister prophecy of cosmic foulness from beyond the stars. To stop the imminent destruction of the world, the She-Devil with a Sword must trek from the deserts south of Hyrkania all the way to the northern shores of the Vilayet Sea to face down the insidious invaders from Mars - not to mention the serpent-men, metamorlocks, and ancient, angry monster-gods that she meets along the way!