When they had finished they followed the trail upward toward the pass through which it led across the hills, and as they went Tarzan sought to question Thoar concerning his country and its people, but so limited is the primitive vocabulary of the Sagoths and so meager Thoar's knowledge of this language that they found communication difficult and Tarzan determined to master Thoar's tongue. Considerable experience in learning new dialects and languages rendered the task far from difficult and as the ape-man never for a moment relinquished a purpose he intended to achieve, nor ever abandoned a task that he had set himself until it had been successfully concluded, he made rapid progress which was greatly facilitated by the interest which Thoar took in instructing him. As they reached the summit of the low hills, they saw, hazily in the far distance, what appeared to be a range of lofty mountains. "There," said Thoar, pointing, "lies Zoram." "What is Zoram?" asked Tarzan. "It is my country," replied the warrior. "It lies in the Mountains of the Thipdars." This was the second time that Tarzan had heard a reference to thipdars. Tar-gash had said the aeroplane was a thipdar and now Thoar spoke of the Mountains of the Thipdars. "What is a thipdar?" he asked. Thoar looked at him in astonishment. "From what country do you come," he demanded, "that you do not know what a thipdar is and do not speak the language of the gilaks?" "I am not of Pellucidar," said Tarzan. "I could believe that," said Thoar, "if there were any other place from which you could be, but there is not, except Molop Az, the flaming sea upon which Pellucidar floats. But the only inhabitants of the Molop Az are the little demons, who carry the dead who are buried in the ground, piece by piece, down to Molop Az, and while I have never seen one of these little demons I am sure that they are not like you." "No," said Tarzan, "I am not from Molop Az, yet sometimes I have thought that the world from which I come is inhabited by demons, both large and small." As they hunted and ate and slept and marched together, these three creatures found their confidence in one another increasing so that even Tar-gash looked no longer with suspicion upon Thoar, and though they represented three distinct periods in the ascent of man, each separated from the other by countless thousands of years, yet they had so much in common that the advance which man had made from Tar-gash to Tarzan seemed scarcely a fair recompense for the time and effort which Nature must have expended.