He waited for any further objections, but none came, though Karl still looked unhappy. So he took pity on him and added gently: “And I bet Joe will beat me to the top.”

The big man relaxed, and a slow grin spread across his face. “All the same, Bill, I wish you’d taken someone else.”

“I wanted one man who’d been down before, and we can’t both go. As for Herr Doctor Professor Sergeant Myron, Laura says he’s still two kilos overweight. Even shaving off that moustache didn’t help.”

“Who’s your number three?”

“I still haven’t decided. That depends on Laura.”

“She wants to go herself.”

“Who doesn’t? But if she turns up at the top of her own fitness list, I’ll be very suspicious.”

As Lieut-Commander Mercer gathered up his papers and launched himself out of the cabin, Norton felt a brief stab of envy. Almost all the crew—about eighty-five per cent, by his minimum estimate—had worked out some sort of emotional accommodation. He had known ships where the captain had done the same, but that was not his way. Though discipline aboard the Endeavour was based very largely on the mutual respect between highly trained and intelligent men and women, the commander needed something more to underline his position. His responsibility was unique, and demanded a certain degree of isolation, even from his closest friends. Any liaison could be damaging to morale, for it was almost impossible to avoid charges of favouritism. For this reason, affairs spanning more than two degrees of rank were firmly discouraged; but apart from this, the only rule regulating shipboard sex was “So long as they don’t do it in the corridors and frighten the simps”.

There were four superchimps aboard Endeavour, though strictly speaking the name was inaccurate, because the ship’s non-human crew was not based on chimpanzee stock. In zero gravity, a prehensile tail is an enormous advantage, and all attempts to supply these to humans had turned into embarrassing failures. After equally unsatisfactory results with the great apes, the Superchimpanzee Corporation had turned to the monkey kingdom.

Blackie, Blondie, Goldie and Brownie had family trees whose branches included the most intelligent of the Old and New World monkeys, plus synthetic genes that had never existed in nature. Their rearing and education had probably cost as much as that of the average spaceman, and they were worth it. Each weighed less than thirty kilos and consumed only half the food and oxygen of a human being, but each could replace 2.75 men for housekeeping, elementary cooking, tool-carrying and dozens of other routine jobs.

That 2.75 was the Corporation’s claim, based on innumerable time-and-motion studies. The figure, though surprising and frequently challenged, appeared to be accurate, for simps were quite happy to work fifteen hours a day and did not get bored by the most menial and repetitious tasks. So they freed human beings for human work; and on a spaceship, that was a matter of vital importance.

Unlike the monkeys who were their nearest relatives Endeavour’s simps were docile, obedient and uninquisitive. Being cloned, they were also sexless, which eliminated awkward behavioural problems. Carefully housetrained vegetarians, they were very clean and didn’t smell; they would have made perfect pets, except that nobody could possibly have afforded them.

Despite these advantages, having simps on board involved certain problems. They had to have their own quarters—inevitably labelled “The Monkey House”. Their little mess-room was always spotless, and was well equipped with TV, games equipment and programmed teaching machines. To avoid accidents, they were absolutely forbidden to enter the ship’s technical areas; the entrances to all these were colour-coded in red, and the simps were conditioned so that it was psychologically impossible for them to pass the visual barriers.

There was also a communications problem. Though they had an equivalent IQ of sixty, and could understand several hundred words of English, they were unable to talk. It had proved impossible to give useful vocal chords either to apes or monkeys, and they therefore had to express themselves in sign language.

The basic signs were obvious and easily learned, so that everyone on board ship could understand routine messages. But the only man who could speak fluent Simpish was their handler—Chief Steward McAndrews.

It was a standing joke that Sergeant Ravi McAndrews looked rather like a simp—which was hardly an insult, for with their short, tinted pelts and graceful movements they were very handsome animals. They were also affectionate, and everyone on board had his favourite; Commander Norton’s was the aptly-named Goldie.

But the warm relationship which one could so easily establish with simps created another problem, often used as a powerful argument against their employment in space. Since they could only be trained for routine, low-grade tasks, they were worse than useless in an emergency; they could then be a danger to themselves and to their human companions. In particular, teaching them to use spacesuits had proved impossible, the concepts involved being quite beyond their understanding.

No one liked to talk about it, but everybody knew what had to be done if a hull was breached or the order came to abandon ship. It had happened only once; then the simp handler had carried out his instructions more than adequately. He was found with his charges, killed by the same poison. Thereafter the job of euthing was transferred to the chief medical officer, who it was felt would have less emotional involvement. Norton was very thankful that this responsibility, at least, did not fall upon the captain’s shoulders. He had known men he would have killed with far fewer qualms than he would Goldie.

In the clear, cold atmosphere of Rama, the beam of the searchlight was completely invisible. Three kilometres down from the central Hub, the hundred-metre wide oval of light lay across a section of that colossal stairway. A brilliant oasis in the surrounding darkness, it was sweeping slowly towards the curved plain still five kilometres below; and in its centre moved a trio of antlike figures, casting long shadows before them.

It had been, just as they had hoped and expected, a completely uneventful descent. They had paused briefly at the first platform, and Norton had walked a few hundred metres along the narrow, curving ledge before starting the slide down to the second level. Here they had discarded their oxygen gear, and revelled in the strange luxury of being able to breathe without mechanical aids. Now they could explore in comfort, freed from the greatest danger that confronts a man in space, and forgetting all worries about suit integrity and oxygen reserve.

By the time they had reached the fifth level, and there was only one more section to go, gravity had reached almost half its terrestrial value. Rama’s centrifugal spin was at last exerting its real strength; they were surrendering themselves to the implacable force which rules every planet, and which can exert a merciless price for the smallest slip. It was still very easy to go downwards; but the thought of the return, up those thousands upon thousands of steps, was already beginning to prey upon their minds.

The stairway had long ago ceased its vertiginous downward plunge and was now flattening out towards the horizontal. The gradient was now only about 1 in 5; at the beginning, it had been 5 in 1. Normal walking was now both physically, and psychologically, acceptable; only the lowered gravity reminded them that they were not descending some great stairway on Earth. Norton had once visited the ruins of an Aztec temple, and the feelings he had then experienced came echoing back to him—amplified a hundred times. Here was the same sense of awe and mystery, and the sadness of the irrevocably vanished past. Yet the scale here was so much greater, both in time and space, that the mind was unable to do it justice; after a while, it ceased to respond. Norton wondered if, sooner or later, he would take even Rama for granted.