Tarzan Triumphs

Tarzan, having acclimated to life in London, is called back to his former home in the jungle to investigate the activities at a mining encampment.

A letter from Jane, who is nursing British troops, asks Tarzan's help in obtaining a malaria serum extractable from jungle plants. Tarzan and Boy set out across the desert looking for the plants. Along the way they befriend a stranded American lady magician.

A young couple die in a plane crash in the jungle. Their son is found by Tarzan and Jane who name him Boy and raise him as their own. Five years later a search party comes to find the young heir to millions of dollars. Jane agrees, against Tarzan's will, to lead them to civilization.

A scientific expedition happens to discover that gold exists on Tarzan's escarpment. The villainous Medford and Vandermeer kidnap Jane and Boy to extort from Tarzan the location of the gold.

Circus owner Buck Rand kidnaps Boy to perform in his show. He forces a pilot to fly him, Boy and his animal trainer out of the jungle. Tarzan and Jane follow them to New York.