[2] Tarzan and Boy, on their way to meet Jane, who is returning from nursing work in Britain to support the war effort, rescue an "Amazon" woman from an attack by a black panther.

Telling Boy to wait for him, Tarzan carries the woman through a mountain pass to the valley where her city of Palmyria is located.

After they reunite with Jane, a group of explorers, led by Sir Guy Henderson, discover the bracelet Cheeta has, and its markings are matched to other relics supposedly from a lost city of Amazons.

Boy and the party are captured by the Amazons, and their queen declares that in lieu of the death penalty for invading their city, they will all be forced to work the rest of their lives in the Palmyrian quarries with the other men they keep for labor.

Tarzan races to Palmyria, meets Ballister and Anders, and backs them into a mud bog in which they sink and die.