The last word that we received from Perry before his messages faltered and died out was to the effect that David Innes, first Emperor of Pellucidar, was languishing in a dark dungeon in the land of the Korsars, far across continent and ocean from his beloved land of Sari, which lies upon a great plateau not far inland from the Lural Az. I THE O-220 Tarzan of the apes paused to listen and to sniff the air. Had you been there you could not have heard what he heard, or had you you could not have interpreted it. You could have smelled nothing but the mustiness of decaying vegetation, which blended with the aroma of growing things. The sounds that Tarzan heard came from a great distance and were faint even to his ears; nor at first could he definitely ascribe them to their true source, though he conceived the impression that they heralded the coming of a party of men. Buto the rhinoceros, Tantor the elephant or Numa the lion might come and go through the forest without arousing more than the indifferent interest of the Lord of the Jungle, but when man came Tarzan investigated, for man alone of all creatures brings change and dissension and strife wheresoever he first sets foot. Reared to manhood among the great apes without knowledge of the existence of any other creatures like himself, Tarzan had since learned to anticipate with concern each fresh invasion of his jungle by these two-footed harbingers of strife. Among many races of men he had found friends, but this did not prevent him from questioning the purposes and the motives of whosoever entered his domain. And so today he moved silently through the middle terrace of his leafy way in the direction of the sounds that he had heard. As the distance closed between him and those he went to investigate, his keen ears cataloged the sound of padding, naked feet and the song of native carriers as they swung along beneath their heavy burdens. And then to his nostrils came the scent spoor of black men and with it, faintly, the suggestion of another scent, and Tarzan knew that a white man was on safari before the head of the column came in view along the wide, well-marked game trail, above which the Lord of the Jungle waited. Near the head of the column marched a young white man, and when Tarzan's eyes had rested upon him for a moment as he swung along the trail they impressed their stamp of approval of the stranger within the ape-man's brain, for in common with many savage beasts and primitive men Tarzan possessed an uncanny instinct in judging aright the characters of strangers whom he met. Turning about, Tarzan moved swiftly and silently through the trees until he was some little distance ahead of the marching safari, then he dropped down into the trail and awaited its coming.