The Sentinel

by Arthur C. Clarke

  It was surprising how many questions Prince Henry managed to ask in the thirty minutes that had been allotted for his tour of the freighter. They were not the routine questions that people asked out of politeness, quite uninterested in the answers. H.R.H. Prince Henry knew a lot about spaceships, and Captain Saunders felt completely exhausted when he handed his distinguished guest back to the reception committee, which had been waiting outside the Centaurus with well-simulated patience.

  “Thank you very much, Captain,” said the prince as they shook hands in the air lock. “I’ve not enjoyed myself so much for ages. I hope you have a pleasant stay in England, and a successful voyage.” Then his retinue whisked him away, and the port officials, frustrated until now, came aboard to check the ship’s papers.

  “Well,” said Mitchell when it was all over, “what did you think of our Prince of Wales?”

  “He surprised me,” answered Saunders frankly. “I’d never have guessed he was a prince. I always thought they were rather dumb. But heck, he knew the principles of the Field Drive! Has he ever been up in space?”

  “Once, I think. Just a hop above the atmosphere in a Space Force ship. It didn’t even reach orbit before it came back again—but the Prime Minister nearly had a fit. There were questions in the House and editorials in the Times. Everyone decided that the heir to the throne was too valuable to risk in these newfangled inventions. So, though he has the rank of commodore in the Royal Space Force, he’s never even been to the moon.”

  “The poor guy,” said Captain Saunders.

  He had three days to burn, since it was not the captain’s job to supervise the loading of the ship or the preflight maintenance. Saunders knew skippers who hung around breathing heavily on the necks of the servicing engineers, but he wasn’t that type. Besides, he wanted to see London. He had been to Mars and Venus and the moon, but this was his first visit to England. Mitchell and Chambers filled him with useful information and put him on the monorail to London before dashing off to see their own families. They would be returning to the spaceport a day before he did, to see that everything was in order. It was a great relief having officers one could rely on so implicitly: they were unimaginative and cautious, but thoroughgoing almost to a fault. If they said that everything was shipshape, Saunders knew he could take off without qualms.

  The sleek, streamlined cylinder whistled across the carefully tailored landscape. It was so close to the ground, and traveling so swiftly, that one could only gather fleeting impressions of the towns and fields that flashed by. Everything, thought Saunders, was so incredibly compact, and on such a Lilliputian scale. There were no open spaces, no fields more than a mile long in any direction. It was enough to give a Texan claustrophobia—particularly a Texan who also happened to be a space pilot.

  The sharply defined edge of London appeared like the bulwark of some walled city on the horizon. With few exceptions, the buildings were quite low—perhaps fifteen or twenty stories in height. The monorail shot through a narrow canyon, over a very attractive park, across a river that was presumably the Thames, and then came to rest with a steady, powerful surge of deceleration. A loud-speaker announced, in a modest voice that seemed afraid of being overheard: “This is Paddington. Passengers for the North please remain seated.” Saunders pulled his baggage down from the rack and headed out into the station.

  As he made for the entrance to the Underground, he passed a bookstall and glanced at the magazines on display. About half of them, it seemed, carried photographs of Prince Henry or other members of the royal family. This, thought Saunders, was altogether too much of a good thing. He also noticed that all the evening papers showed the prince entering or leaving the Centaurus, and bought copies to read in the subway—he begged its pardon, the “Tube.”

  The editorial comments had a monotonous similarity. At last, they rejoiced, England need no longer take a back seat among the space-going nations. Now it was possible to operate a space fleet without having a million square miles of desert: the silent, gravity-defying ships of today could land, if need be, in Hyde Park, without even disturbing the ducks on the Serpentine. Saunders found it odd that this sort of patriotism had managed to survive into the age of space, but he guessed that the British had felt it pretty badly when they’d had to borrow launching sites from the Australians, the Americans, and the Russians.

  The London Underground was still, after a century and a half, the best transport system in the world, and it deposited Saunders safely at his destination less than ten minutes after he had left Paddington. In ten minutes the Centaurus could have covered fifty thousand miles; but space, after all, was not quite so crowded as this. Nor were the orbits of space craft so tortuous as the streets Saunders had to negotiate to reach his hotel. All attempts to straighten out London had failed dismally, and it was fifteen minutes before he completed the last hundred yards of his journey.

  He stripped off his jacket and collapsed thankfully on his bed. Three quiet, carefree days all to himself: it seemed too good to be true.

  It was. He had barely taken a deep breath when the phone rang.

  “Captain Saunders? I’m so glad we found you. This is the BBC. We have a program called ‘In Town Tonight’ and we were wondering . . . ”

  The thud of the air-lock door was the sweetest sound Saunders had heard for days. Now he was safe; nobody could get at him here in his armored fortress, which would soon be far out in the freedom of space. It was not that he had been treated badly: on the contrary, he had been treated altogether too well. He had made four (or was it five?) appearances on various TV programs; he had been to more parties than he could remember; he had acquired several hundred new friends and (the way his head felt now) forgotten all his old ones.

  “Who started the rumor,” he said to Mitchell as they met at the port, “that the British were reserved and standoffish? Heaven help me if I ever meet a demonstrative Englishman.”

  “I take it,” replied Mitchell, “that you had a good time.”

  “Ask me tomorrow,” Saunders replied. “I may have reintegrated my psyche by then.”

  “I saw you on that quiz program last night,” remarked Chambers. “You looked pretty ghastly.”

  “Thank you: that’s just the sort of sympathetic encouragement I need at the moment. I’d like to see you think of a synonym for ‘jejune’ after you’d been up until three in the morning.”

  “Vapid,” replied Chambers promptly.

  “Insipid,” said Mitchell, not to be outdone.

  “You win. Let’s have those overhaul schedules and see what the engineers have been up to.”

  Once seated at the control desk, Captain Saunders quickly became his usual efficient self. He was home again, and his training took over. He knew exactly what to do, and would do it with automatic precision. To right and left of him, Mitchell and Chambers were checking their instruments and calling the control tower.

  It took them an hour to carry out the elaborate preflight routine. When the last signature had been attached to the last sheet of instructions, and the last red light on the monitor panel had turned to green, Saunders flopped back in his seat and lit a cigarette. They had ten minutes to spare before take-off.

  “One day,” he said, “I’m going to come to England incognito to find what makes the place tick. I don’t understand how you can crowd so many people onto one little island without it sinking.”

  “Huh,” snorted Chambers. “You should see Holland. That makes England look as wide open as Texas.”

  “And then there’s this royal family business. Do you know, wherever I went everybody kept asking me how I got on with Prince Henry—what we’d talked about—didn’t I think he was a fine guy, and so on. Frankly, I got fed up with it. I can’t imagine how you’ve managed to stand it for a thousand years.”

  “Don’t think that the royal family’s been popular all the time,” replied Mitchell. “Remember what happened to Charles the First? And some of the things we said about the early Georges
were quite as rude as the remarks your people made later.”

  “We just happen to like tradition,” said Chambers. “We’re not afraid to change when the time comes, but as far as the royal family is concerned—well, it’s unique and we’re rather fond of it. Just the way you feel about the Statue of Liberty.”

  “Not a fair example. I don’t think it’s right to put human beings up on a pedestal and treat them as if they’re—well, minor deities. Look at Prince Henry, for instance. Do you think he’ll ever have a chance of doing the things he really wants to do? I saw him three times on TV when I was in London. The first time he was opening a new school somewhere; then he was giving a speech to the Worshipful Company of Fishmongers at the Guildhall (I swear I’m not making that up), and finally he was receiving an address of welcome from the mayor of Podunk, or whatever your equivalent is.” (”Wigan,” interjected Mitchell.) “I think I’d rather be in jail than live that sort of life. Why can’t you leave the poor guy alone?”

  For once, neither Mitchell nor Chambers rose to the challenge. Indeed, they maintained a somewhat frigid silence. That’s torn it, thought Saunders. I should have kept my big mouth shut; now I’ve hurt their feelings. I should have remembered that advice I read somewhere: “The British have two religions—cricket and the royal family. Never attempt to criticize either.”

  The awkward pause was broken by the radio and the voice of the spaceport controller.

  “Control to Centaurus. Your flight lane clear. O.K. to lift.”

  “Take-off program starting—now!” replied Saunders, throwing the master switch. Then he leaned back, his eyes taking in the entire control panel, his hands clear of the board but ready for instant action.

  He was tense but completely confident. Better brains than his—brains of metal and crystal and flashing electron streams—were in charge of the Centaurus now. If necessary, he could take command, but he had never yet lifted a ship manually and never expected to do so. If the automatics failed, he would cancel the take-off and sit here on Earth until the fault had been cleared up.

  The main field went on, and weight ebbed from the Centaurus. There were protesting groans from the ship’s hull and structure as the strains redistributed themselves. The curved arms of the landing cradle were carrying no load now; the slightest breath of wind would carry the freighter away into the sky.

  Control called from the tower: “Your weight now zero: check calibration.”

  Saunders looked at his meters. The upthrust of the field would now exactly equal the weight of the ship, and the meter readings should agree with the totals on the loading schedules. In at least one instance this check had revealed the presence of a stowaway on board a spaceship—the gauges were as sensitive as that.

  “One million, five hundred and sixty thousand, four hundred and twenty kilograms,” Saunders read off from the thrust indicators. “Pretty good—it checks to within fifteen kilos. The first time I’ve been underweight, though. You could have taken on some more candy for that plump girl friend of yours in Port Lowell, Mitch.”

  The assistant pilot gave a rather sickly grin. He had never quite lived down a blind date on Mars which had given him a completely unwarranted reputation for preferring statuesque blondes.

  There was no sense of motion, but the Centaurus was now falling up into the summer sky as her weight was not only neutralized but reversed. To the watchers below, she would be a swiftly mounting star, a silver globule climbing through and beyond the clouds. Around her, the blue of the atmosphere was deepening into the eternal darkness of space. Like a bead moving along an invisible wire, the freighter was following the pattern of radio waves that would lead her from world to world.

  This, thought Captain Saunders, was his twenty-sixth take-off from Earth. But the wonder would never die, nor would he ever outgrow the feeling of power it gave him to sit here at the control panel, the master of forces beyond even the dreams of mankind’s ancient gods. No two departures were ever the same; some were into the dawn, some toward the sunset, some above a cloud-veiled Earth, some through clear and sparkling skies. Space itself might be unchanging, but on Earth the same pattern never recurred, and no man ever looked twice at the same landscape or the same sky. Down there the Atlantic waves were marching eternally toward Europe, and high above them—but so far below the Centaurus!—the glittering bands of cloud were advancing before the same winds. England began to merge into the continent, and the European coast line became foreshortened and misty as it sank hull down beyond the curve of the world. At the frontier of the west, a fugitive stain on the horizon was the first hint of America. With a single glance, Captain Saunders could span all the leagues across which Columbus had labored half a thousand years ago.

  With the silence of limitless power, the ship shook itself free from the last bonds of Earth. To an outside observer, the only sign of the energies it was expending would have been the dull red glow from the radiation fins around the vessel’s equator, as the heat loss from the mass-converters was dissipated into space.

  “14:03:45,” wrote Captain Saunders neatly in the log. “Escape velocity attained. Course deviation negligible.”

  There was little point in making the entry. The modest 25,000 miles an hour that had been the most unattainable goal of the first astronauts had no practical significance now, since the Centaurus was still accelerating and would continue to gain speed for hours. But it had a profound psychological meaning. Until this moment, if power had failed, they would have fallen back to Earth. But now gravity could never recapture them: they had achieved the freedom of space, and could take their pick of the planets. In practice, of course, there would be several kinds of hell to pay if they did not pick Mars and deliver their cargo according to plan. But Captain Saunders, like all spacemen, was fundamentally a romantic. Even on a milk run like this he would sometimes dream of the ringed glory of Saturn or the somber Neptunian wastes, lit by the distant fires of the shrunken sun.

  An hour after take-off, according to the hallowed ritual, Chambers left the course computer to its own devices and produced the three glasses that lived beneath the chart table. As he drank the traditional toast to Newton, Oberth, and Einstein, Saunders wondered how this little ceremony had originated. Space crews had certainly been doing it for at least sixty years: perhaps it could be traced back to the legendary rocket engineer who made the remark, “I’ve burned more alcohol in sixty seconds than you’ve ever sold across this lousy bar.”

  Two hours later, the last course correction that the tracking stations on Earth could give them had been fed into the computer. From now on, until Mars came sweeping up ahead, they were on their own. It was a lonely thought, yet a curiously exhilarating one. Saunders savored it in his mind. There were just the three of them here—and no one else within a million miles.

  In the circumstances, the detonation of an atomic bomb could hardly have been more shattering than the modest knock on the cabin door . . .

  Captain Saunders had never been so startled in his life. With a yelp that had already left him before he had a chance to suppress it, he shot out of his seat and rose a full yard before the ship’s residual gravity field dragged him back. Chambers and Mitchell, on the other hand, behaved with traditional British phlegm. They swiveled in their bucket seats, stared at the door, and then waited for their captain to take action.

  It took Saunders several seconds to recover. Had he been confronted with what might be called a normal emergency, he would already have been halfway into a space-suit. But a diffident knock on the door of the control cabin, when everybody else in the ship was sitting beside him, was not a fair test.

  A stowaway was simply impossible. The danger had been so obvious, right from the beginning of commercial space flight, that the most stringent precautions had been taken against it. One of his officers, Saunders knew, would always have been on duty during loading; no one could possibly have crept in unobserved. Then there had been the detailed preflight inspection, carried out by both M
itchell and Chambers. Finally, there was the weight check at the moment before take-off; that was conclusive. No, a stowaway was totally . . .

  The knock on the door sounded again. Captain Saunders clenched his fists and squared his jaw. In a few minutes, he thought, some romantic idiot was going to be very, very sorry.

  “Open the door, Mr. Mitchell,” Saunders growled. In a single long stride, the assistant pilot crossed the cabin and jerked open the hatch.

  For an age, it seemed, no one spoke. Then the stowaway, wavering slightly in the low gravity, came into the cabin. He was completely self-possessed, and looked very pleased with himself.

  “Good afternoon, Captain Saunders,” he said, “I must apologize for this sudden intrusion.”

  Saunders swallowed hard. Then, as the pieces of the jigsaw fell into place, he looked first at Mitchell, then at Chambers. Both of his officers stared guilelessly back at him with expressions of ineffable innocence. “So that’s it,” he said bitterly. There was no need for any explanations: everything was perfectly clear. It was easy to picture the complicated negotiations, the midnight meetings, the falsification of records, the off-loading of nonessential cargoes that his trusted colleagues had been conducting behind his back. He was sure it was a most interesting story, but he didn’t want to hear about it now. He was too busy wondering what the Manual of Space Law would have to say about a situation like this, though he was already gloomily certain that it would be of no use to him at all.

  It was too late to turn back, of course: the conspirators wouldn’t have made an elementary miscalculation like that. He would just have to make the best of what looked to be the trickiest voyage in his career.