A famed geologist, accompanied by his infant son Erik and pet leopard cub, is drowned in a canoe accident while searching for mineral deposits in Africa. Years later, journalist Myrna Claudel and photographer Ken Matson parachute into the jungle and persuade Tarzan to help them find a wild boy believed to be the geologist's son. Upon reaching Zagunda territory, the trio persuade tribal chief Buhara to help them find the boy. During the search, Buhara is attacked and nearly killed by his brother, Nagambi, who hopes to usurp Buhara's crown. Young Erik finds the wounded chief and takes him to his cave, where Tarzan later discovers them and helps Erik nurse Buhara back to health. Meanwhile, Myrna and Ken, who have followed Tarzan into the Zagunda jungle, with the help of Tarzan's chimp, are ambushed by Nagambi's warriors, and Ken is killed. Tarzan rescues Myrna, and Buhara kills his brother. The jungle boy, now known as Jukaro, heeds Tarzan's advice and returns to civilization with Myrna.