arm under a rung. Clenching and unclenching his fists, he waited until the muscle cramps had faded away. When he felt quite comfortable, he opened his eyes and slowly turned to face Rama.
His first impression was one of blueness. The glare that filled the sky could not have been mistaken for sunlight; it might have been that of an electric arc. So Rama’s sun, Norton told himself, must be hotter than ours. That should interest the astronomers.
And now he understood the purpose of those mysterious trenches, the Straight Valley and its five companions. They were nothing less than gigantic strip-lights. Rama had six linear suns, symmetrically ranged around its interior. From each a broad fan of light was aimed across the central axis, to shine upon the far side of the world. Norton wondered if they could be switched alternately to produce a cycle of light and darkness, or whether this was a planet of perpetual day.
Too much staring at those blinding bars of light had made his eyes hurt again; he was not sorry to have a good excuse to close them for a while. It was not until then, when he had almost recovered from his initial visual shock, that he was able to devote himself to a much more serious problem.
Who, or what, had switched on the lights of Rama?
By the most sensitive tests that man could apply to it, this world was sterile. But now something was happening that could not be explained by the action of natural forces. There might not be life here, but there could be consciousness, awareness; robots might be waking after a sleep of eons. Perhaps this outburst of light was an unprogrammed, random spasm—a last dying gasp of machines that were responding wildly to the warmth of a new sun and would soon lapse again into quiescence, this time forever.
Yet Norton could not believe such a simple explanation. Bits of the jigsaw puzzle were beginning to fall into place, though many were still missing: the absence of all signs of wear, for example, and the feeling of newness, as if Rama had just been created.
These thoughts might have inspired fear, even terror. Somehow, though, they did nothing of the sort. On the contrary, Norton felt a sense of exhilaration, almost of delight. There was far more here to discover than they had ever dared to hope. Wait, he said to himself, until the Rama Committee hears about this!
Then, with calm determination, he opened his eyes again and began a careful inventory of everything he saw.
First he had to establish some kind of reference system. He was looking at the largest enclosed space ever seen by man, and he needed a mental map to find his way around it.
The feeble gravity was little help, for with an effort of will he could switch “up” and “down” in any direction he pleased. But some directions were psychologically dangerous; whenever his mind skirted these, he had to vector it hastily away.
Safest of all was to imagine that he was at the bowl-shaped bottom of a gigantic well, sixteen kilometers wide and fifty deep. The advantage of this image was that there could be no danger of falling farther. Nevertheless, it had some serious defects.
He could pretend that the scattered towns and cities, and the differently colored and textured areas, were all securely fixed to the towering walls. The various complex structures that could be seen hanging from the dome overhead were perhaps no more disconcerting than the pendent candelabra in some great concert hall on Earth. What was quite unacceptable was the Cylindrical Sea.
There it was, hallway up the well shaft—a band of water, wrapped completely around it, with no visible means of support. There could be no doubt that it was water; it was a vivid blue, flecked with brilliant sparkles from the few remaining ice floes. But a vertical sea forming a complete circle twenty kilometers up in the sky was such an unsettling phenomenon that after a while he began to seek an alternative.
That was when his mind switched the scene through ninety degrees. Instantly, the deep well became a long tunnel, capped at each end. “Down” was obviously in the direction of the ladder and the stairway he had just ascended; and now, with this perspective, he was at last able to appreciate the true vision of the architects who had built this place.
He was clinging to the face of a curving, sixteen-kilometer-high cliff, the upper half of which