Tarzan is then captured by the insane yet beautiful queen Nemone of its hereditary enemy, Cathne, the City of Gold, capital of the land of Onthar.

This novel is perhaps best known for two scenes; in the first, Tarzan is forced to fight Cathne's strongest man Phobeg in its arena.

This lion, however, is of a breed specifically selected for endurance, and ultimately Tarzan must turn to face him, though aware that without a knife he can do little but delay the inevitable.

His own lion ally, Jad-bal-ja, whom he had raised from a cub, arrives and intervenes, killing Belthar and saving Tarzan.

(The only other lost city that Tarzan visits more than once is Opar, which appears in four novels and is referenced in a juvenile story).