Paulvitch still lived and sought vengeance against Tarzan. As part of his plot, he lured Tarzan's young son away from London. But the boy escaped, with the aid of the great ape Akut. They fled to the savage African jungles where Tarzan had been reared. There the civilized boy had to learn to meet the great beasts and face the dangers only his father had ever conquered. But he grew in time into Korak the Killer, almost as mighty as Tarzan. Korak found a friend in Meriem, whom he rescued from a raiding Arab band. Then he discovered that the dangers of the jungle were nothing compared to those devised by men.