the strain of his uncertainty. Suddenly he encountered another door. He paused to listen, but heard nothing coming from the room to which it led. Cautiously he went on.
At the door he paused and peeped in. A Subterranean was working on a taas ship just inside. Breathlessly he hugged the wall. Then, after a tense moment, he peeped in again. The creature had moved away from the machine and was standing with his back toward the door.
Quietly he went past, every muscle in his body tingling. Time and again he glanced over his shoulder to see if the Subterranean had detected his presence. Seeing nothing behind him but the corridor twisting away, he breathed a sigh of relief. Then before he realized it he found himself facing the open of the crater.
More alert than ever he hugged the corridor wall and peered into the open. Hundreds of skeletons toiled around the taas extractors. Unending lines trudged back and forth from the dumps to their respective machines. Subterranean guards watched over them. In the center of the crater stood a group of the grotesque creatures, as if engaged in some silent conversation.
Bob searched his immediate vicinity for a hovering guard. Fortunately for him none were nearer than the center of the abyss. He wondered if he could make a rapid ascent to the crater's rim without being observed. His hands trembled a trifle now. But he steeled himself to the inevitable. Make it or not, he was going to try. His blood raced hot, like searing metal through his veins. He breathed hard, keeping his taas tube in direct line with the group. Resolved to wipe them out at first indication of having been seen, he edged his way to the mouth of the corridor.
For an instant he paused there, determinedly. With his free hand he pressed the second, third and fourth buttons on his chest strap. Instantly the propellers on his back gained velocity. He was jerked violently off his feet and into the air, rising within a foot or two of the rugged side of the abyss.
Higher into the air—like a rocket, he soared. Eyes glued on the guards below; taas tube held ready, he watched the skeletons and their guards diminish in size as he rose. Then he saw the group suddenly disband and amble away in different directions. He wondered if he had been seen. He noticed one guard moving across the crater bottom at a swift pace. Then he realized that he was going beyond the rim.
IT dawned upon him suddenly that he had forgotten to ask Larkin how to operate the shoulder device for forward flight. He swore grimly as he overshot the rim and continued upward. For a moment he had visions of bashing his skull against the roof of the great earth bubble into which the Scienta had been drawn. Desperately he pushed the buttons to slow his flight upward. The propellers slowed magically. Yet he continued to rise slowly.
Then he recalled that he had seen the flying Subterraneans kick their feet in descending from their hovering taas ships. Hopefully he kicked his own, throwing himself off balance in the air. Jubilantly he felt himself being carried forward by the reaction. He realized suddenly that the feet played an important part in the flying of the machine, acting like the tail of a bird in flight.
Swinging his feet upward he was carried forward. But, unused to such motion, his legs grew suddenly tired. But not before he had been carried from above the open abyss. He looked down. The crater rim was directly below. Silently praying that he had not been seen, he pressed the buttons again. The vibration of the propellers decreased. Slowly he descended until his feet finally touched the ground.
He slumped over on his side and lay still, breathing hard. Realization that he had outwitted the ever alert Subterraneans, a feat Larkin had said was absolutely impossible, made him suddenly weak. Sweat streamed from his forehead and stung his eyes like fire. He ran a trembling hand over them and looked toward the opposite side of the crater. Far below he saw the laboring skeletons. They seemed no larger than dwarfs from the distance and gave no indication of any excitement taking place there.
But across the abyss lay his objective. He had dropped down in a small clearing that overlooked the crater. Around him the thick, impenetrable brush blocked any way of advance on foot. It broke off sheer at the edge of the crater. He realized, as he looked over the ground, that he would be compelled to fly around the crater to attain the other side. To fly directly across the abyss would be fatal.
But he must get to the skeletons now or never. If he ever hoped to learn of Patti’s fate, the opportunity could not be overlooked or passed by. Yet, unaccustomed as he was to the handling of the Subterranean fight machine, he dreaded the ordeal of going into the air again.
It has been said that love will drive a man to do things, where all other incentives fail. It must have been Bob Allen’s great love for Patti Marsden that drove him into the air again. He sent himself as high as he dared and guided himself around the crater with his dangling feet. As he went he realized that he was learning quickly how to handle himself. By way of experiment he tried various stunts by working his feet. He dove headlong, performed a complete loop, swung left and right, and by the time he reached his objective he was jubiliant over his success in mastering the Subterraneans' own means of individual flight.
But what he saw lying on the ground under him caused him to sober quickly. In various attitudes, three human skeletons, bones gleaming white against the ground, glared up at him. Keeping well out of sight, away from the crater’s edge, he alighted near the trail and advanced toward them on foot.
He cursed softly, viciously, at the murderous Subterraneans who had stripped these bones of their flesh, snuffed out their lives with a single ray. With a great sob he bent down over a skeleton. It was smaller than the others, much smaller. The jaws hung open as if death had come in unspeakable agony. He studied the white teeth. They were small and pearly. His hands trembled as in palsy. A bit of dark hair clung to the skull. It was soft and alive, but shortcropped. Yet Patti Marsden had had hair like that, and it had been bobbed, shingled close in the back. He touched it with a shaking hand and looked again at the pearly teeth, wondering if the lips he had kissed there in the pilot house, had once covered them in the redness of life and youth.
His wandering eyes alighted on the ghastly hands. The bones, held together by hardened sinews, were
