Arthur Clarke - The Last Theorem

Thrust was failing. The Diana was losing power.

Training brought discipline. Discipline prevented panic. Nevertheless, Natasha’s heart was in her mouth as she cast off her restraining straps to act. Her first thought was that something had happened to the sail. Perhaps the anti-spin devices had failed and the rigging was twisting itself up. But as she checked the meters that read out the tensions of the shroud lines, what they told her was strange. On one side of the sail the meters were reading normally. On the other the value was dropping slowly before her eyes.

Then understanding came. Natasha grabbed the periscope for a wide-angle scan of the edges of the sail. Yes! There was the trouble…and it could have come from only one cause.

The huge sharp-edged shadow that had begun to slide across the gleaming silver of Diana ’s sail told the story. Darkness was spreading over one edge of Natasha’s ship as though a cloud had passed between her and the sun, cutting off light, putting a stop to the tiny pressure that drove the craft.

There were no such clouds in space.

Natasha grinned as she swung the periscope sunward. Optical filters clicked automatically into position to save her from instant blindness, and what she saw was precisely what she had expected to see. It looked as though a giant boy’s kite were sliding across the face of the sun.

Natasha recognized the shape at once. Thirty kilometers astern, South America’s Santa Maria was trying to produce an artificial eclipse for Natasha.

“Ha, Senhor Ronaldinho Olsos,” Natasha whispered, “that’s the oldest trick in the book!”

So it was, and a perfectly legal one, too. Back in the days of ocean racing, skippers had done their best to rob opponents of their wind.

But only the incompetents were caught that way, and incompetent, Natasha de Soyza Subramanian was not. Her tiny computer—the size of a matchbook but the equivalent of a thousand human number-crunching experts—considered the problem for a brief fraction of a moment and quickly spat out course corrections.

Two could play at that game. Grinning, Natasha reached out to disable the autopilot and make the adjustments to the trim in her rigging….

That didn’t happen.

The tiny windlasses stayed frozen. Suddenly they were receiving no orders at all, either from the autopilot computer or from the human being that should have been controlling everything.

Solar yacht Diana was no longer under way. The vast sail began to tip….

And then to bend….

And then the ripples in the fabric began to grow into great, irregular billows. And the flimsy material that was the sail reached, and passed, its maximum tolerated stress.

The commodore saw at once that Diana was in trouble. Indeed, the whole fleet did, and radio discipline evaporated in a flash. Ron Olsos was the first to demand a chemical-powered tender to take him off his own ship so that he could help search for Natasha Subramanian in the collapsing ruin that had been the space yacht Diana. He wasn’t the last. Within another hour the race had dissolved into more than a score of vessels of all kinds milling about the crumpled mass that had once been beautiful Diana, doing their best to avoid colliding with one another. The spacecraft that possessed the capability of man-in-space technology suited up as many of their crews as they could and searched.

They searched every fold of the immense crumpled sail—visually when they had to, and with infrared viewers when those were present. These viewers would instantly pick up the tiny signal of a warm human body anywhere in the destroyed sail.

They searched all the space around destroyed Diana, on the chance that somehow Natasha had been flung free through some unknown accident….

Above all, they searched Diana ’s tiny cabin.

That didn’t take long. With only herself aboard there was no need for privacy; Diana ’s capsule amounted to only a few cubic meters of space, and no possible place to hide.

But she wasn’t there. As far as the searchers could tell, Natasha Subramanian wasn’t anywhere at all.

What the three fourths of the Subramanian family that remained on Earth had resolved to do was carry on with as normal a life as was possible, with the other quarter of the family gallivanting through cislunar space in a contraption of plastic and buckyball carbon. Accordingly, once they had sent Natasha their final good luck message, Ranjit had got on his bike to head for his office. Myra had seen the possibility of a whole hour, maybe two, for her to try to catch up on what her increasing backlog of journals had to say about some of the hotter subjects in the area of AI and prostheses. Such gifts of a few personal hours were not frequent. They came when young Robert was asleep, or when he was at his special school, or when he was, as now, dutifully following the housemaid around, helping her—or, more accurately, “helping” her—with her early-morning tasks of making beds and tidying rooms.

So, with a cooling cup of tea on the table before her—and, of course, with the news programs playing on her room screen in case, however improbably, something unexpected occurred in Natasha’s race—Myra was trying to make sense of some of her journals when she heard the sound of her son’s heartbroken sobbing.

She looked up and saw the maid carrying him into the room. “I don’t know what happened, missus,” the maid said, sounding struck. “We were emptying out the wastebaskets when Robert suddenly sat down and began to cry. Robert never cries, missus!”

Which Myra, of course, knew as well as she did. But there it was. So Myra did what untold billions of other mothers have done, all the way from the australopithecines. She took her son in her arms and rocked him soothingly, murmuring into his ear. It didn’t stop the crying, no, but the tears simmered down to sobs. Myra was asking herself whether this unusual and troubling—but certainly not life-threatening—development warranted calling her husband at his office, when there was a stifled shriek from the maid. Myra looked up.

There on the screen was the image of her daughter’s solar yacht. Apart from the fact that one edge was, ever so slightly, tipped up, it looked exactly as it had an hour earlier. But now there was a red banner underneath the image that said “Accident in lunar race?” And when the audio volume was turned up, there was no question mark in the agitated remarks of the newscaster. Something bad had happened to Diana. Worst of all, Diana ’s pilot—which was to say, Myra’s beloved daughter—was not answering distress calls from the commodore, and it seemed that whatever had gone wrong with the solar yacht had somehow abducted its pilot.

Myra Subramanian’s terrible worry was perhaps the most personal distress anyone in the world can feel, but she was not alone. The more the tender vessels dug into the puzzle of what had happened to Diana, the more hopelessly unanswerable the puzzle seemed.

Emergency workers from the commodore’s yacht had long since suited up and reached Diana ’s command capsule. They managed to gain entrance, searched it, found no trace of its pilot. But that was not the worst. More detailed examination showed that the register on the capsule’s one air lock showed unequivocally that it had not been opened since Natasha herself had entered, to begin the race. So Natasha was not only missing; she had never even left her command capsule.

All of which, of course, was quite impossible. And also unarguably true.

Also of course, the commodore and his staff had several dozen other problems to try to solve, all at once. There were the six other solar yachts, no longer in an orderly line, now in some danger of colliding with one another as their pilots were distracted by what had happened to the seventh of their group. The order went out to each of them to furl their sails and await pickup. That would leave the craft as six little bullets of matter that would have to be followed and somehow steered into parking orbits that would not threaten other space traffic…but not right away. Those problems could be dealt with in an orderly fashion, when time permitted.