Wealthy John (True Boardman) and Alice Clayton (Kathleen Kirkham) sail to Africa with their young son. But after a nasty mutiny, only the child survives. In the jungle, the boy is accepted by a motherly gorilla, who raises him as her own. Years later, a team sets out to locate the long-lost Clayton boy, only to find that he's now Tarzan (Elmo Lincoln), a savage who bears no traces of his upper-class origins. But, when natives attack the search party, it's the brutish Tarzan who must save them.