Now they were moving quietly beneath the broken clouds. Though their speed had not slackened, the roar of the wind had suddenly died away, for they were travelling with it through emptiness. They could even converse comfortably, across the thirty feet of space that still separated them.
‘Dr Elwin,’ Harper called, ‘are you OK?’
‘Yes, George,’ said the scientist, perfectly calmly. ‘Now what do we do?’
‘We must stop lifting. If we go any higher, we won’t be able to breathe—even with the filters.’
‘You’re right. Let’s get back into balance.’
The angry humming of the packs died to a barely audible electric whine as they cut out the emergency circuits. For a few minutes they yo-yoed up and down on their nylon rope—first one uppermost, then the other—until they managed to get into trim. When they had finally stabilised, they were drifting at a little below thirty thousand feet. Unless the Levvies failed—which, after their overload, was quite possible—they were out of immediate danger.
Their troubles would start when they tried to return to Earth.
No men in all history had ever greeted a stranger dawn. Though they were tired and stiff and cold, and the dryness of the thin air made every breath rasp in their throats, they forgot all these discomforts as the first dim glow spread along the jagged eastern horizon. The stars faded one by one; last to go, only minutes before the moment of daybreak, was the most brilliant of all the space stations—Pacific Number Three, hovering twenty-two thousand miles above Hawaii. Then the sun lifted above a sea of nameless peaks, and the Himalayan day had dawned.
It was like watching sunrise on the Moon. At first, only the highest mountains caught the slanting rays, while the surrounding valleys remained flooded with inky shadows. But slowly the line of light marched down the rocky slopes, and more and more of this harsh, forbidding land climbed into the new day.
Now, if one looked hard enough, it was possible to see signs of human life. There were a few narrow roads, thin columns of smoke from lonely villages, glints of reflected sunlight from monastery roofs. The world below was waking, wholly unaware of the two spectators poised so magically fifteen thousand feet above.
During the night, the wind must have changed direction several times, and Harper had no idea where they were. He could not recognise a single landmark. They could have been anywhere over a five-hundred mile-long strip of Nepal and Tibet.
The immediate problem was to choose a landing place—and that soon, for they were drifting rapidly toward a jumble of peaks and glaciers where they could hardly expect to find help. The wind was carrying them in a northeasterly direction, toward China. If they floated over the mountains and landed there, it might be weeks before they could get in contact with one of the UN Famine Relief Centres and find their way home. They might even be in some personal danger, if they descended out of the sky in an area where there was only an illiterate and superstitious peasant population.
‘We’d better get down quickly,’ said Harper. ‘I don’t like the look of those mountains.’ His words seemed utterly lost in the void around them. Although Dr Elwin was only ten feet away, it was easy to imagine that his companion could not hear anything he said. But at last the Doctor nodded his head, in almost reluctant agreement.
‘I’m afraid you’re right—but I’m not sure we can make it, with this wind. Remember—we can’t go down as quickly as we can rise.’
That was true enough; the power-packs could be charged at only a tenth of their discharge rate. If they lost altitude and pumped gravitational energy back into them too fast, the cells would overheat and probably explode. The startled Tibetans (or Nepalese?) would think that a large meteorite had detonated in their sky. And no one would ever know exactly what had happened to Dr Jules Elwin and his promising young assistant.
Five thousand feet above the ground, Harper began to expect the explosion at any moment. They were falling swiftly, but not swiftly enough; very soon they would have to decelerate, lest they hit at too high a speed. To make matters worse, they had completely miscalculated the air speed at ground level. That infernal, unpredictable wind was blowing a near-gale once more. They could see streamers of snow, torn from exposed ridges, waving like ghostly banners beneath them. While they had been moving with the wind, they were unaware of its power; now they must once again make the dangerous transition between stubborn rock and softly yielding sky.
The air current was funnelling them into the mouth of a canyon. There was no chance of lifting above it. They were committed, and would have to choose the best landing place they could find.
The canyon was narrowing at a fearsome rate. Now it was little more than a vertical cleft, and the rocky walls were sliding past at thirty or forty miles an hour. From time to time random eddies would swing them to the right, then the left; often they missed collisions by only a few feet. Once, when they were sweeping scant yards above a ledge thickly covered with snow, Harper was tempted to pull the quick-release that would jettison the Levitator. But that would be jumping from the frying pan into the fire: they might get safely back onto firm ground only to find themselves trapped unknown miles from all possibility of help.
Yet even at this moment of renewed peril, he felt very little fear. It was all like an exciting dream—a dream from which he would presently wake up to find himself safely in his own bed. This fantastic adventure could not really be happening to him….
‘George!’ shouted the Doctor. ‘Now’s our chance—if we can snag that boulder!’
They had only seconds in which to act. At once, they both began to play out the nylon rope, until it hung in a great loop beneath them, its lowest portion only a yard above the racing ground. A large rock, some twenty feet high, lay exactly in their line of flight; beyond it, a wide patch of snow gave promise of a reasonably soft landing.
The rope skittered over the lower curves of the boulder, seemed about to slip clear, then caught beneath an overhang. Harper felt the sudden jerk. He was swung around like a stone on the end of a sling.
I never thought that snow could be so hard, he told himself. After that there was a brief and brilliant explosion of light; then nothing.
He was back at the university, in the lecture room. One of the professors was talking, in a voice that was familiar, yet somehow did not seem to belong here. In a sleepy, halfhearted fashion, he ran through the names of his college instructors. No, it was certainly none of them. Yet he knew the voice so well, and it was undoubtedly lecturing to
someone
.
‘…still quite young when I realised that there was something wrong with Einstein’s Theory of Gravitation. In particular, there seemed to be a fallacy underlying the Principle of Equivalence. According to this, there is no way of distinguishing between the effects produced by gravitation and those of acceleration.
‘But this is clearly false. One can create a uniform acceleration; but a uniform gravitational field is impossible, since it obeys an inverse square law, and therefore must vary even over quite short distances. So tests can easily be devised to distinguish between the two cases, and this made me wonder if…’
The softly spoken words left no more impression on Harper’s mind than if they were in a foreign language. He realised dimly that he
should
understand all this, but it was too much trouble to look for the meaning. Anyway, the first problem was to decide where he was.
Unless there was something wrong with his eyes, he was in complete darkness. He blinked, and the effort brought on such a splitting headache that he gave a cry of pain.
‘George! Are you all right?’
Of course! That had been Dr Elwin’s voice, talking softly there in the darkness. But talking to
whom
?
‘I’ve got a terrible headache. And there’s a pain in my side when I try to move. What’s happened? Why is it dark?’
‘You’ve had concussion—and I think you’ve cracked a rib. Don’t do any unnecessary talking. You’ve been unconscious all day. It’s night again, and we’re inside the tent. I’m saving our batteries.’
The glare from the flashlight was almost blinding when Dr Elwin switched it on, and Harper saw the walls of the tiny tent around them. How lucky that they had brought full mountaineering equipment, just in case they got trapped on Everest. But perhaps it would only prolong the agony….
He was surprised that the crippled scientist had managed, without any assistance, to unpack all their gear, erect the tent, and drag him inside. Everything was laid out neatly: the first-aid kit, the concentrated-food cans, the water containers, the tiny red gas cylinders for the portable stove. Only the bulky Levitator units were missing; presumably they had been left outside to give more room.
‘You were talking to someone when I woke up,’ Harper said. ‘Or was I dreaming?’ Though the indirect light reflected from the walls of the tent made it hard to read the other’s expression, he could see that Elwin was embarrassed. Instantly, he knew why, and wished that he had never asked the question.
The scientist did not believe that they would survive. He had been recording his notes, in case their bodies were ever discovered. Harper wondered bleakly if he had already recorded his last will and testament.
Before Elwin could answer, he quickly changed the subject.
‘Have you called Lifeguard?’
‘I’ve been trying every half hour, but I’m afraid we’re shielded by the mountains. I can hear them, but they don’t receive us.’
Dr Elwin picked up the little recorder-transceiver, which he had unstrapped from its normal place on his wrist, and switched it on.
‘This is Lifeguard Four,’ said a faint mechanical voice, ‘listening out now.’
During the five-second pause, Elwin pressed the SOS button, then waited.
‘This is Lifeguard Four, listening out now.’
They waited for a full minute, but there was no acknowledgment of their call. Well, Harper told himself grimly, it’s too late to start blaming each other now. Several times while they had been drifting above the mountains they had debated whether to call the global rescue service, but had decided against it, partly because there seemed no point in doing so while they were still air-borne, partly because of the unavoidable publicity that would follow. It was easy to be wise after the event: who would have dreamed that they would land in one of the few places beyond Lifeguard’s reach?
Dr Elwin switched off the transceiver, and the only sound in the little tent was the faint moaning of the wind along the mountain walls within which they were doubly trapped—beyond escape, beyond communication.
‘Don’t worry,’ he said at last. ‘By morning, we’ll think of a way out. There’s nothing we can do until dawn—except make ourselves comfortable. So drink some of this hot soup.’
Several hours later, the headache no longer bothered Harper. Though he suspected that a rib was indeed cracked, he had found a position that was comfortable as long as he did not move, and he felt almost at peace with the world.
He had passed through successive phases of despair, anger at Dr Elwin, and self-recrimination at having become involved in such a crazy enterprise. Now he was calm again, though his mind, searching for ways of escape, was too active to allow sleep.
Outside the tent, the wind had almost died away, and the night was very still. It was no longer completely dark, for the Moon had risen. Though its direct rays would never reach them here, there must be some reflected light from the snows above. Harper could just make out a dim glow at the very threshold of vision, seeping through the translucent heat-retaining walls of the tent.
First of all, he told himself, they were in no immediate danger. The food would last for at least a week; there was plenty of snow that could be melted to provide water. In a day or two, if his rib behaved itself, they might be able to take off again—this time, he hoped, with happier results.
From not far away there came a curious, soft thud, which puzzled Harper until he realised that a mass of snow must have fallen somewhere. The night was now so extraordinarily quiet that he almost imagined he could hear his own heartbeat; every breath of his sleeping companion seemed unnaturally loud.
Curious, how the mind was distracted by trivialities! He turned his thoughts back to the problem of survival. Even if he was not fit enough to move, the Doctor could attempt the flight by himself. This was a case where one man would have just as good a chance of success as two.
There was another of those soft thuds, slightly louder this time. It was a little odd, Harper thought fleetingly, for snow to move in the cold stillness of the night. He hoped that there was no risk of a slide; having had no time for a clear view of their landing place, he could not assess the danger. He wondered if he should awaken the Doctor, who must have had a good look around before he erected the tent. Then, fatalistically, he decided against it; if there
was
an impending avalanche, it was not likely that they could do much to escape.
Back to problem number one. Here was an interesting solution well worth considering. They could attach the transceiver to one of the Levvies and send the whole thing aloft. The signal would be picked up as soon as the unit left the canyon, and Lifeguard would find them within a few hours—or, at the very most, a few days.
Of course, it would mean sacrificing one of the Levvies, and if nothing came of it, they would be in an even worse plight. But all the same…
What was that?
This was no soft thudding of loose snow. It was a faint but unmistakable ‘click’, as of one pebble knocking against another. And pebbles did not move themselves.
You’re imagining things, Harper told himself. The idea of anyone, or anything, moving around one of the high Himalayan passes in the middle of the night was completely ridiculous. But his throat became suddenly dry, and he felt the flesh crawl at the back of his neck. He had heard
something
, and it was impossible to argue it away.
Damn the Doctor’s breathing; it was so noisy that it was hard to focus on any sounds from outside. Did this mean that he, Elwin, fast asleep though he was, had also been alerted by his ever-watchful subconscious? He was being fanciful again….