Rendezvous With Rama

chapter 17. Spring
During the first "nights" on Rama, it had not been easy to sleep. The darkness and the mysteries it concealed were oppressive, but even more unsettling was the silence. Absence of noise is not a natural condition; all human senses require some input. If they are deprived of it, the mind manufactures its own substitutes.

And so many sleepers had complained of strange noises - even of voices - which were obviously illusions, because those awake had heard nothing. Surgeon-Commander Ernst had prescribed a very simple and effective cure; during the sleeping period, the camp was now lulled by gentle, unobtrusive background music.

This night, Commander Norton found the cure inadequate. He kept straining his ears into the darkness, and he knew what he was listening for. But though a very faint breeze did caress his face from time to time, there was no sound that could possibly be taken for that of a distant, rising wind. Nor did either of the exploring parties report anything unusual.

At least, around Ship's midnight, he went to sleep. There was always a man on watch at the communications console, in case of any urgent messages. No other precautions seemed necessary.

Not even a hurricane could have created the sound that did wake him, and the whole camp, in a single instant. It seemed that the sky was falling, or that Rama had split open and was tearing itself apart. First there was a rending crack, then a long-drawn-out series of crystalline crashes like a million glasshouses being demolished. It lasted for minutes, though it seemed like hours; it was still continuing, apparently moving away into the distance, when Norton got to the message centre.

"Hub Control! What's happened?"

"Just a moment, Skipper. It's over by the Sea. We're getting the light on it."

Eight kilometres overhead, on the axis of Rama, the searchlight began to swing its beam out across the plain. It reached the edge of the Sea, then started to track along it, scanning around the interior of the world. A quarter of the way round the cylindrical surface, it stopped.

Up there in the sky - or what the mind still persisted in calling the sky - something extraordinary was happening. At first, it seemed to Norton that the Sea was boiling. It was no longer static and frozen in the grip of an eternal winter; a huge area, kilometres across, was in turbulent movement. And it was changing colour; a broad band of white was marching across the ice.

Suddenly a slab perhaps a quarter of a kilometre on a side began to tilt upwards like an opening door. Slowly and majestically, it reared into the sky, glittering and sparkling in the beam of the searchlight. Then it slid back and vanished underneath the surface, while a tidal wave of foaming water raced outwards in all directions from its point of submergence.

Not until then did Commander Norton fully realize what was happening. The ice was breaking up. All these days and weeks, the Sea had been thawing, far down in the depths. It was hard to concentrate because of the crashing roar that still filled the world and echoed round the sky, but he tried to think of a reason for so dramatic a convulsion. When a frozen lake or river thawed on Earth, it was nothing like this...

But of course! It was obvious enough, now that it had happened. The Sea was thawing from beneath as the solar heat seeped through the hull of Rama. And when ice turns into water, it occupies less volume...

So the Sea had been sinking below the upper layer of ice, leaving it unsupported. Day by day the strain bad been building up; now the band of ice that encircled the equator of Rama was collapsing, like a bridge that had lost its central pier. It was splintering into hundreds of floating islands that would crash and jostle into each other until they too melted. Norton's blood ran suddenly cold, when he remembered the plans that were being made to reach New York by sledge...

The tumult was swiftly subsiding; a temporary stalemate had been reached in the war between ice and water. In a few hours, as the temperature continued to rise, the water would win and the last vestiges of ice would disappear. But in the long run, ice would be the victor, as Rama rounded the sun and set forth once more into the interstellar night.

Norton remembered to start breathing again; then he called the party nearest the Sea. To his relief, Lieutenant Rodrigo answered at once. No, the water hadn't reached them. No tidal wave had come sloshing over the edge of the cliff. "So now we know," he added very calmly, "why there is a cliff." Norton agreed silently; but that hardly explains, he thought to himself, why the cliff on the southern shore is ten times higher...

The Hub searchlight continued to scan round the world. The awakened Sea was steadily calming, and the boiling white foam no longer raced outwards from capsizing ice floes. In fifteen minutes, the main disturbance was over.

But Rama was no longer silent; it had awakened from its sleep, and ever and again there came the sound of grinding ice as one berg collided with another.

Spring had been a little late, Norton told himself, but winter had ended.

And there was that breeze again, stronger than ever. Rama had given him enough warnings; it was time to go.

As he neared the halfway mark, Commander Norton once again felt gratitude to the darkness that concealed the view above - and below. Though he knew that more than ten thousand steps still lay ahead of him, and could picture the steeply ascending curve in his mind's eye, the fact that he could see only a small portion of it made the prospect more bearable.

This was his second ascent, and he had learned from his mistakes on the first. The great temptation was to climb too quickly in this low gravity; every step was so easy that it was very hard to adopt a slow, plodding rhythm. But unless one did this, after the first few thousand steps strange aches developed in the thighs and calves. Muscles that one never knew existed started to protest, and it was necessary to take longer and longer periods of rest. Towards the end he had spent more time resting than climbing, and even then it was not enough. He had suffered painful leg cramps for the next two days, and would have been almost incapacitated had he not been back in the zero-gravity environment of the ship.

So this time he had started with almost painful slowness, moving like an old man. He had been the last to leave the plain, and the others were strung out along the half-kilometre of stairway above him; he could see their lights moving up the invisible slope ahead.

He felt sick at heart at the failure of his mission, and even now hoped that this was only a temporary retreat. When they reached the Hub, they could wait until any atmospheric disturbances had ceased. Presumably, it would be a dead calm there, as at the centre of a cyclone, and they could wait out the expected storm in safety.

Once again, he was jumping to conclusions, drawing dangerous analogies from Earth. The meteorology of a whole world, even under steady-state conditions, was a matter of enormous complexity. After several centuries of study, terrestrial weather forecasting was still not absolutely reliable. And Rama was not merely a completely novel system; it was also undergoing rapid changes, for the temperature had risen several degrees in the last few hours. Yet still there was no sign of the promised hurricane, though there had been a few feeble gusts from apparently random directions.

They had now climbed five kilometres, which in this low and steadily diminishing gravity was equivalent to less than two on Earth. At the third level, three kilometres from the axis, they rested for an hour, taking light refreshments and massaging leg muscles. This was the last point at which they could breathe in comfort; like old-time Himalayan mountaineers, they had left their oxygen supplies here, and now put them on for the final ascent.

An hour later, they had reached the top of the stairway - and the beginning of the ladder. Ahead lay the last, vertical kilometre, fortunately in a gravity field only a few per cent of Earth's. Another thirty-minute rest, a careful check of oxygen, and they were ready for the final lap.

Once again, Norton made sure that all his men were safely ahead of him, spaced out at twenty-metre intervals along the ladder. From now on, it would be a slow, steady haul, extremely boring. The best technique was to empty the mind of all thoughts and to count the rungs as they drifted by - one hundred, two hundred, three hundred, four hundred...

He had just reached twelve hundred and fifty when he suddenly realized that something was wrong. The light shining on the vertical surface immediately in front of his eyes was the wrong colour - and it was much too bright.

Commander Norton did not even have time to check his ascent, or to call a warning to his men. Everything happened in less than a second.

In a soundless concussion of light, dawn burst upon Rama.