As the Korsar ship turned back to port the dirigible dropped low above the flagship of the Sarian fleet and greetings were exchanged between David and his rescuers--men from another world whom he had never seen. The Emperor was half starved and very thin and weak from his long period of confinement, but otherwise he had been unharmed, and great was the rejoicing aboard the ships of Sari as they turned back to cross the Korsar Az toward their own land. Tarzan was afraid to accompany the fleet back to Sari for fear that their rapidly diminishing store of fuel would not be sufficient to complete the trip and carry them back to the outer world. He followed the fleet only long enough to obtain from David explicit directions for reaching the polar opening from the city of Korsar. "We have another errand to fulfill first," said Jason to Tarzan. "We must return Thoar and Jana to Zoram." "Yes," said the ape-man, "and drop these two Korsars off near their city. I have thought of all that and we shall have fuel enough for that purpose." "I am not going to return with you," said Jason. "I wish to be put aboard Ja's flagship." "What?" exclaimed Tarzan. "You are going to remain here?" "This expedition was undertaken at my suggestion. I feel responsible for the life and safety of every man in it and I shall never return to the outer world while the fate of Lieutenant Von Horst remains a mystery." "But how can you find Von Horst if you go back to Sari with the fleet?" asked Tarzan. "I shall ask David Innes to equip an expedition to go in search of him," replied Jason, "and with such an expedition made up of native Pellucidarians I shall stand a very much better chance of finding him than we would in the O-220." "I quite agree with you," said Tarzan, "and if you are unalterably determined to carry out your project, we will lower you to Ja's ship immediately." As the O-220 dropped toward Ja's flagship and signalled it to heave to, Jason gathered what belongings he wished to take with him, including rifles and revolvers and plenty of ammunition. These were lowered first to Ja's ship, while Jason bid farewell to his companions of the expedition. "Good-bye, Jana," he said, after he had shaken hands with the others. The girl made no reply, but instead turned to her brother. "Good-bye, Thoar," she said. "Good-bye?" he asked. "What do you mean?" "I am going to Sari with the man I love," replied The Red Flower of Zoram. * * * * * TARZAN AT THE EARTH'S CORE An urgent message from Pellucidar, that world of primitive men and primeval jungles that lies inside the crust of the Earth, called on Tarzan of the Apes for assistance.