The Quests must abandon ship when the Sea Quest catches fire. By dawn, the men, separated from Bandit and the boys, are rescued, but the others swim to an island inhabited by large yet friendly tree-dwelling apes who take them in. A pair of down-on-their-luck poachers get news of Dr. Quest's offer of reward for the return of the boys. A ransom, they think, will pay more, making them keen to find the boys and remove them roughly from their simian hosts.
—statmanjeff