In this 10th volume of John Norman's Gor series, Tarl Cabot must prove his final loyalty to the harsh and caste-bound planet known as counter-earth. "Surrender Gor," reads a message sent from the Others, a mysterious people from the worlds of steel. Either the proud rulers of Gor submit or be destroyed. Now Tarl Cabot is leaving the decadent city of Port Kar to wander in the wilds of Gor, taking up the sword to defend his rulers and enemies, the Priest-kings. For he knows that the fate of his home planet, Earth, is inextricably tied to the fate of Gor.
Nomads of Gor is my favorite of the series. It has all the best elements of Tarl Cabot's world, without too much of the boring rehash of the state of the Gorean slave girl.