A violent thunderstorm has Tarzan, Jane and the rest of the gorilla family seeking shelter in nearby caves. Along the way Tarzan feels unsure that he can protect the family as well as Kerchak did. When they reach the cave they think they are safe but they have chosen the same cave that banished gorilla Tublat lives in. Tarzan is no physical match for Tublat and must use his superior cunning and ingenuity to defeat him.