Collected Stories Of Arthur C. Clarke (17 page)

I was impressed, but at the same time I felt a little sceptical.

‘That’s all very well,’ I said, ‘but surely the deeper you go the less there’ll be to see. The pressure will make any cavities impossible, and after a few miles there will simply be a homogeneous mass getting denser and denser.’

‘Quite likely,’ agreed the Professor. ‘But I can still learn a lot from the transmission characteristics. Anyway, we’ll see when we get there!’

That was four months ago; and yesterday I saw the result of that research. When I answered his invitation the Professor was clearly excited, but he gave me no hint of what, if anything, he had discovered. He showed me his improved equipment and raised the new receiver from its bath. The sensitivity of the pickups had been greatly improved, and this alone had effectively doubled the range, altogether apart from the increased transmitter power. It was strange to watch the steel framework slowly turning and to realise that it was exploring regions, which, in spite of their nearness, man might never reach.

When we entered the hut containing the display equipment, the Professor was strangely silent. He switched on the transmitter, and even though it was a hundred yards away I could feel an uncomfortable tingling. Then the cathode ray tube lit up and the slowly revolving timebase drew the picture I had seen so often before. Now, however, the definition was much improved owing to the increased power and sensitivity of the equipment. I adjusted the depth control and focussed on the Underground, which was clearly visible as a dark lane across the faintly luminous screen. While I was watching, it suddenly seemed to fill with mist and I knew that a train was going through.

Presently I continued the descent. Although I had watched this picture many times before, it was always uncanny to see great luminous masses floating toward me and to know that they were buried rocks – perhaps the debris from the glaciers of fifty thousand years ago. Dr Clayton had worked out a chart so that we could identify the various strata as they were passed, and presently I saw that I was through the alluvial soil and entering the great clay saucer which traps and holds the city’s artesian water. Soon that too was passed, and I was dropping down through the bedrock almost a mile below the surface.

The picture was still clear and bright, though there was little to see, for there were now few changes in the ground structure. The pressure was already rising to a thousand atmospheres; soon it would be impossible for any cavity to remain open, for the rock itself would begin to flow. Mile after mile I sank, but only a pale mist floated on the screen, broken sometimes when echoes were returned from pockets or lodes of denser material. They became fewer and fewer as the depth increased – or else they were now so small that they could no longer be seen.

The scale of the picture was, of course, continually expanding. It was now many miles from side to side, and I felt like an airman looking down upon an unbroken cloud ceiling from an enormous height. For a moment a sense of vertigo seized me as I thought of the abyss into which I was gazing. I do not think that the world will ever seem quite solid to me again.

At a depth of nearly ten miles I stopped and looked at the Professor. There had been no alteration for some time, and I knew that the rock must now be compressed into a featureless, homogeneous mass. I did a quick mental calculation and shuddered as I realised that the pressure must be at least thirty tons to the square inch. The scanner was revolving very slowly now, for the feeble echoes were taking many seconds to struggle back from the depths.

‘Well, Professor,’ I said, ‘I congratulate you. It’s a wonderful achievement. But we seem to have reached the core now. I don’t suppose there’ll be any change from here to the centre.’

He smiled a little wryly. ‘Go on,’ he said. ‘You haven’t finished yet.’

There was something in his voice that puzzled and alarmed me. I looked at him intently for a moment; his features were just visible in the blue-green glow of the cathode ray tube.

‘How far down can this thing go?’ I asked, as the interminable descent started again.

‘Fifteen miles,’ he said shortly. I wondered how he knew, for the last feature I had seen at all clearly was only eight miles down. But I continued the long fall through the rock, the scanner turning more and more slowly now, until it took almost five minutes to make a complete revolution. Behind me I could hear the Professor breathing heavily, and once the back of my chair gave a crack as his fingers gripped it.

Then, suddenly, very faint markings began to reappear on the screen. I leaned forward eagerly, wondering if this was the first glimpse of the world’s iron core. With agonising slowness the scanner turned through a giant angle, then another. And then—

I leaped suddenly out of the chair, cried ‘My God!’ and turned to face the Professor. Only once before in my life had I received such an intellectual shock – fifteen years ago, when I had accidentally turned on the radio and heard of the fall of the first atomic bomb. That had been unexpected, but this was inconceivable. For on the screen had appeared a grid of faint lines, crossing and recrossing to form a perfectly symmetrical lattice.

I know that I said nothing for many minutes, for the scanner made a complete revolution while I stood frozen with surprise. Then the Professor spoke in a soft, unnaturally calm voice.

‘I wanted you to see it for yourself before I said anything. That picture is now thirty miles in diameter, and those squares are two or three miles on a side. You’ll notice that the vertical lines converge and the horizontal ones are bent into arcs. We’re looking at part of an enormous structure of concentric rings; the centre must lie many miles to the north, probably in the region of Cambridge. How much further it extends in the other direction we can only guess.’

‘But what
is
it, for heaven’s sake?’

‘Well, it’s clearly artificial.’

‘That’s ridiculous! Fifteen miles down!’

The Professor pointed to the screen again. ‘God knows I’ve done my best,’ he said, ‘but I can’t convince myself that Nature could make anything like that.’

I had nothing to say, and presently he continued: ‘I discovered it three days ago, when I was trying to find the maximum range of the equipment. I can go deeper than this, and I rather think that the structure we can see is so dense that it won’t transmit my radiations any further.

‘I’ve tried a dozen theories, but in the end I keep returning to one. We know that the pressure down there must be eight or nine thousand atmospheres, and the temperature must be high enough to melt rock. But normal matter is still almost empty space. Suppose that there is life down there – not organic life, of course, but life based on partially condensed matter, matter in which the electron shells are few or altogether missing. Do you see what I mean? To such creatures, even the rock fifteen miles down would offer no more resistance than water – and we and all our world would be as tenuous as ghosts.’

‘Then that thing we can see—’

‘Is a city, or its equivalent. You’ve seen its size, so you can judge for yourself the civilisation that must have built it. All the world we know – our oceans and continents and mountains – is nothing more than a film of mist surrounding something beyond our comprehension.’

Neither of us said anything for a while. I remember feeling a foolish surprise at being one of the first men in the world to learn the appalling truth; for somehow I never doubted that it was the truth. And I wondered how the rest of humanity would react when the revelation came.

Presently I broke into the silence. ‘If you’re right,’ I said, ‘why have they – whatever they are – never made contact with us?’

The Professor looked at me rather pityingly. ‘We think we’re good engineers,’ he said, ‘but how could
we
reach
them
? Besides, I’m not at all sure that there haven’t been contacts. Think of all the underground creatures and the mythology – trolls and cobalds and the rest. No, it’s quite impossible – I take it back. Still the idea
is
rather suggestive.’

All the while the pattern on the screen had never changed: the dim network still glowed there, challenging our sanity. I tried to imagine streets and buildings and the creatures going among them, creatures who could make their way through the incandescent rock as a fish swims through water. It was fantastic … and then I remembered the incredibly narrow range of temperature and pressures under which the human race exists.
We
, not they, were the freaks, for almost all the matter in the universe is at temperatures of thousands or even millions of degrees.

‘Well,’ I said lamely, ‘what do we do now?’

The Professor leaned forward eagerly. ‘First we must learn a great deal more, and we must keep this an absolute secret until we are sure of the facts. Can you imagine the panic there would be if this information leaked out? Of course, the truth’s inevitable sooner or later, but we may be able to break it slowly.

‘You’ll realise that the geological surveying side of my work is now utterly unimportant. The first thing we have to do is to build a chain of stations to find the extent of the structure. I visualise them at ten-mile intervals towards the north, but I’d like to build the first one somewhere in South London to see how extensive the thing is. The whole job will have to be kept as secret as the building of the first radar chain in the late thirties.

‘At the same time, I’m going to push up my transmitter power again. I hope to be able to beam the output much more narrowly, and so greatly increase the energy concentration. But this will involve all sorts of mechanical difficulties, and I’ll need more assistance.’

I promised to do my utmost to get further aid, and the Professor hopes that you will soon be able to visit his laboratory yourself. In the meantime I am attaching a photograph of the vision screen, which although not as clear as the original will, I hope, prove beyond doubt that our observations are not mistaken.

I am well aware that our grant to the Interplanetary Society has brought us dangerously near the total estimate for the year, but surely even the crossing of space is less important than the immediate investigation of this discovery which may have the most profound effects on the philosophy and the future of the whole human race.

I sat back and looked at Karn. There was much in the document I had not understood, but the main outlines were clear enough.

‘Yes,’ I said, ‘this is it! Where’s that photograph?’

He handed it over. The quality was poor, for it had been copied many times before reaching us. But the pattern was unmistakable and I recognised it at once.

‘They were good scientists,’ I said admiringly. ‘That’s Callastheon, all right. So we’ve found the truth at last, even if it has taken us three hundred years to do it.’

‘Is that surprising,’ asked Karn, ‘when you consider the mountain of stuff we’ve had to translate and the difficulty of copying it before it evaporates?’

I sat in silence for a while, thinking of the strange race whose relics we were examining. Only once – never again! – had I gone up the great vent our engineers had opened into the Shadow World. It had been a frightening and unforgettable experience. The multiple layers of my pressure suit had made movement very difficult, and despite their insulation I could sense the unbelievable cold that was all around me.

‘What a pity it was,’ I mused, ‘that our emergence destroyed them so completely. They were a clever race, and we might have learned a lot from them.’

‘I don’t think we can be blamed,’ said Karn. ‘We never really believed that anything could exist under those awful conditions of near-vacuum, and almost absolute zero. It couldn’t be helped.’

I did not agree. ‘I think it proves that they were the more intelligent race. After all,
they
discovered us first. Everyone laughed at my grandfather when he said that the radiation he’d detected from the Shadow World must be artificial.’

Karn ran one of his tentacles over the manuscript.

‘We’ve certainly discovered the cause of that radiation,’ he said. ‘Notice the date – it’s just a year before your grandfather’s discovery. The Professor must have got his grant all right!’ He laughed unpleasantly. ‘It must have given him a shock when he saw us coming up to the surface, right underneath him.’

I scarcely heard his words, for a most uncomfortable feeling had suddenly come over me. I thought of the thousands of miles of rock lying below the great city of Callastheon, growing hotter and denser all the way to the Earth’s unknown core. And so I turned to Karn.

‘That isn’t very funny,’ I said quietly. ‘It may be our turn next.’

Inheritance

First published in
New Worlds
, no.3, 1947, as by ‘Charles Willis’

Collected in
Expedition to Earth

As David said, when one falls on Africa from a height of two hundred and fifty kilometres, a broken ankle may be an anti-climax but is none the less painful. But what hurt him most, he pretended, was the way we had all rushed out into the desert to see what had happened to the A.20 and had not come near him until hours later.

‘Be logical, David,’ Jimmy Langford had protested. ‘We knew that you were OK because the base ’copter radioed when it picked you up. But the A.20 might have been a complete write-off.’