A month after the shipwreck. Through Ernst's narration - and the diary he is keeping of events - the family are still struggling with living/surviving off the land and are growing crops, keeping chickens, rearing wild pigs and a goat. But, prompted by the sudden activity of the island's volcano, they are planning to escape and have improved the raft to make it seaworthy. Parsons and Ben have set up home in a squalid cave on a barren outlying island nearby. They fear the family may surprise them and steal the boat. From their island they observe the unsuspecting Robinson's through a telescope. Parsons is still bent on revenging himself on David. Exploring the island the children find a tunnel leading to a cave with a large carved head and a sarcophagus. Christina removes a large black pearl from the cave. David and Ernst investigate the cave, which they surmise to be some kind of ancient burial chamber for native kings. They are trapped when a native canoe arrives indeed carrying a King, his brother, a shaman and several warlike members of a native tribe. The King's brother stages a coup d'etat, but David and Ernst rescue him. The King, an ex-slave, who is deeply suspicious of white men, threatens the family for violating the sacred island. Discovering the King gone, the brother and his men set off in pursuit. Meanwhile, the petulant Emily has wandered into the forest and been captured by Parsons and Ben, who have been observing the King's arrival at the tree house. They in turn are captured by the brother's group. Parsons makes a deal with the brother to recapture the king and to take over the tree house.
