The City And The Stars - Arthur C. Clarke [57]
The sun was high when they left the forest and stood at last before the mountain walls of Lys. Ahead of them the ground rose steeply to the sky in waves of barren rock. Here the river came to an end as spectacular as its beginning, for the ground opened in its path and it sank roaring from sight. Alvin wondered what happened to it, and through what subterranean caves it travelled before it emerged again into the light of day. Perhaps the lost oceans of Earth still existed, far down in the eternal darkness, and this ancient river still felt the call that drew it to the sea.
For a moment Hilvar stood looking at the whirlpool and the broken land beyond. Then he pointed to a gap in the hills.
‘Shalmirane lies in that direction,’ he said confidently. Alvin did not ask how he knew; he assumed that Hilvar’s mind had made brief contact with that of a friend many miles away, and the information he needed had been silently passed to him.
It did not take long to reach the gap, and when they had passed through it they found themselves facing a curious plateau with gently sloping sides. Alvin felt no tiredness now, and no fear—only a taut expectancy and a sense of approaching adventure. What he would discover, he had no conception. That he would discover something he did not doubt at all.
As they approached the summit, the nature of the ground altered abruptly. The lower slopes had consisted of porous, volcanic stone, piled here and there in great mounds of slag. Now the surface turned suddenly to hard, glassy sheets, smooth and treacherous, as if the rock had once run in molten rivers down the mountain.
The rim of the plateau was almost at their feet. Hilvar reached it first, and a few seconds later Alvin overtook him and stood speechless at his side. For they stood on the edge, not of the plateau they had expected, but of a giant bowl half a mile deep and three miles in diameter. Ahead of them the ground plunged steeply downwards, slowly levelling out at the bottom of the valley and rising again, more and more steeply, to the opposite rim. The lowest part of the bowl was occupied by a circular lake, the surface of which trembled continually, as if agitated by incessant waves.
Although it lay in the full glare of the sun, the whole of that great depression was ebon black. What material formed the crater, Alvin and Hilvar could not even guess, but it was black as the rock of a world that had never known a sun. Nor was that all, for lying beneath their feet and ringing the entire crater was a seamless band of metal, some hundred feet wide, tarnished by immeasurable age but still showing no slightest sign of corrosion.
As their eyes grew accustomed to the unearthly scene, Alvin and Hilvar realised that the blackness of the bowl was not as absolute as they had thought. Here and there, so fugitive that they could only see them indirectly, tiny explosions of light were flickering in the ebon walls. They came at random, vanishing as soon as they were born, like the reflections of stars on a broken sea.
‘It’s wonderful!’ gasped Alvin. ‘But what is it?’
‘It looks like a reflector of some kind.’
‘But it’s so black!’
‘Only to our eyes, remember. We do not know what radiations they used.’
‘But surely there must be more than this! Where is the fortress?’
Hilvar pointed to the lake.
‘Look carefully,’ he said.
Alvin stared through the quivering roof of the lake, trying to plumb the secrets it concealed within its depths. At first he could see nothing; then, in the shallows near its edge, he made out a faint reticulation of light and shade. He was able to trace the pattern out towards the centre of the lake until the deepening water hid all further details.
The dark lake had engulfed the fortress. Down there lay the ruins of once mighty buildings, overthrown by time. Yet not all of them had been submerged, for on the far side of the crater Alvin now noticed piles of jumbled stones,