Tarzan had noticed that the roofs of most of the buildings were flat, the few exceptions being those of what he imagined to be the more pretentious public structures. How this city had come to exist in this forgotten part of unexplored Africa the ape-man could not conceive. Better than another, he realized something of the unsolved secrets of the Great Dark Continent, enormous areas of which have as yet been un-touched by the foot of civilized man. Yet he could scarce believe that a city of this size and apparently thus well con-structed could have existed for the generations that it must have been there, without intercourse with the outer world.
Even though it was surrounded by a trackless desert waste, as he knew it to be, he could not conceive that generation after generation of men could be born and die there without at-tempting to solve the mysteries of the world beyond the confines of their little valley.
And yet, here was the city surrounded by tilled land and filled with people!
With the coming of night there arose throughout the jungle the cries of the great cats, the voice of Numa blended with that of Sheeta, and the thunderous roars of the great males reverberated through the forest until the earth trembled, and from within the city came the answering roars of other lions.
A simple plan for gaining entrance to the city had occurred to Tarzan, and now that darkness had fallen he set about to put it into effect. Its success hinged entirely upon the strength of the vines he had seen surmounting the wall toward the east. In this direction he made his way, while from out of the forest about him the cries of the flesh-eaters increased in volume and ferocity. A quarter of a mile intervened between the forest and the city wall -- a quarter of a mile of cultivated land unrelieved by a single tree. Tarzan of the Apes realized his limitations and so he knew that it would undoubtedly spell death for him to be caught in the open space by one of the great black lions of the forest if, as he had already sur-mised, Numa of the pit was a specimen of the forest lion of the valley.
He must, therefore, depend entirely upon his cunning and his speed, and upon the chance that the vine would sustain his weight.
He moved through the middle terrace, where the way is always easiest, until he reached a point opposite the vine-clad portion of the wall, and there he waited, listening and scenting, until he might assure himself that there was no Numa within his immediate vicinity, or, at least, none that sought him. And when he was quite sure that there was no lion close by in the forest, and none in the clearing between himself and the wall, he dropped lightly to the ground and moved stealthily out into the open.
The rising moon, just topping the eastern cliffs, cast its bright rays upon the long stretch of open garden beneath the wall. And, too, it picked out in clear relief for any curious eyes that chanced to be cast in that direction, the figure of the giant ape-man moving across the clearing. It was only chance, of course, that a great lion hunting at the edge of the forest saw the figure of the man halfway between the forest and the wall. Suddenly there broke upon Tarzan's ears a menacing sound. It was not the roar of a hungry lion, but the roar of a lion in rage, and, as he glanced back in the direction from which the sound came, he saw a huge beast moving out from the shadow of the forest toward him.
Even in the moonlight and at a distance Tarzan saw that the lion was huge; that it was indeed another of the black-maned monsters similar to Numa of the pit. For an instant he was impelled to turn and fight, but at the same time the thought of the helpless girl imprisoned in the city flashed through his brain and, without an instant's hesitation, Tarzan of the Apes wheeled and ran for the wall. Then it was that Numa charged.
Numa, the lion, can run swiftly for a short distance, but he lacks endurance. For the period of an ordinary charge he can cover the ground with greater rapidity possibly than any other creature in the world. Tarzan, on the other hand, could run at great speed for long distances, though never as rapidly as Numa when the latter charged.
The question of his fate, then, rested upon whether, with his start he could elude Numa for a few seconds; and, if so, if the lion would then have sufficient stamina remaining to pursue him at a reduced gait for the balance of the distance to the wall.
Never before, perhaps, was staged a more thrilling race, and yet it was run with only the moon and stars to see. Alone and in silence the two beasts sped across the moonlit clearing.
Numa gained with appalling rapidity upon the fleeing man, yet at every bound Tarzan was nearer to the vine-clad wall.
Once the ape-man glanced back. Numa was so close upon him that it seemed inevitable that at the next bound he should drag him down; so close was he that the ape-man drew his knife as he ran, that he might at least give a good account of himself in the last moments of his life.
But Numa had reached the limit of his speed and endurance.
Gradually he dropped behind but he did not give up the pursuit, and now Tarzan realized how much hinged upon the strength of the untested vines.
If, at the inception of the race, only Goro and the stars had looked down upon the contestants, such was not the case at its finish, since from an embrasure near the summit of the wall two close-set black eyes peered down upon the two.
Tarzan was a dozen yards ahead of Numa when he reached the wall. There was no time to stop and institute a search for sturdy stems and safe handholds. His fate was in the hands of chance and with the realization he gave a final spurt and running catlike up the side of the wall among the vines, sought with his hands for something that would sustain his weight. Below him Numa leaped also.
