Tarl Cabot had resumed his allegiance to the Priest-kings, the non-human but benevolent rulers of Earth's orbital twin planet, Gor. And accordingly Tarl knew that the battle for the possesion of the planet was under way-the Kurii, the beastlike invaders, had made their plan. There was a girl, once Judy Thornton of Earth, found in the wilderness of Gor. Captured, as such lovely strangers were on the ruthless world, she was to undergo the training that would make of her a slave girl of great value. But unknown to her captors was the fact that she was a tool of the Kurii, that she carried a programmed message that imperilled the future of Gor. It was for possession of her mind and body that Priest-Kings and Kur-monsters battled, while a planet went its way unsuspecting that its very fate was also locked within the slave collar that graced her neck