PROBABILITY MOON

by Nancy Kress

  Syree, crushed in her chair, gasped to breathe. They couldn’t keep up five gees, of course, not without killing them all. But there were only ninety seconds left … eighty-five …

  She couldn’t speak. The force pressing on her lungs, her throat, choked off all air. But she could hear. Her comlink, sturdier than soft human tissues, came to life with a burst of static, followed by Bazargan’s voice. When had the comlink come back on line? When the artifact failed to detonate? When the Zeus detached it? Earlier? There was no way to tell. And no way to respond; at this distance from Bazargan, the time lag was fifty-four minutes. All Syree could do was listen to words nearly an hour old.

  “Dr. Johnson? Dr. Johnson? What’s happening? Listen, please, we’ve made a discovery here, buried in the Neury Mountains …”

  The pressure on Syree’s chest eased. Lee, or the overrides on the ship, had lessened the acceleration to save the crew. Syree felt her eyeballs burn and bulge outward, suddenly released from their fivefold weight.

  Seventy seconds until the second flyer appeared.

  “ … thinks it’s some sort of probability field, and may be linked to Tas … to the artifact you’re towing toward the space tunnel. Here is Dieter, he can explain much better than I …”

  Syree tried to speak, couldn’t. And there was nothing to say anyway.

  Fifty seconds.

  “Dr. Johnson, Dieter Gruber here. Are you there?”

  On the display the Faller warship picked up speed, moving as fast as it could toward the space tunnel. Presumably to destroy the Zeus before it attacked the skeeter.

  “Scheiss, what is wrong with me? They are an hour away at light speed, Ahmed, of course they don’t answer.”

  Answer. No, Syree couldn’t answer, perhaps not in this life. Too bad, really, she would have liked to work on this fascinating new problem, this probability field. Increasing the likelihood of nuclear emission only in specific ranges and among specific atoms … amazing. Unprecedented. Another reality.

  “Fire,” Peres said.

  The proton beam shot out from the Zeus as the ship sped toward the space tunnel. Bruised, popping eyes tried desperately to focus on the displays. The beam hit the skeeter … and went through it.

  No, Syree thought. Went through a different configuration of matter, with different probabilities of being “observed.” “Detected.” “Intercepted.” And wasn’t.

  The skeeter dived for the tunnel, and within thirty seconds had disappeared into it.

  In another ten seconds the skeeter was back.

  The human flyer popped out of the space tunnel.

  The waiting skeeter destroyed it. Then the skeeter flew once again into the tunnel.

  “Firing on the artifact,” Lee said, and Syree realized that she hadn’t heard Peres give the command, although of course he must have. The detonators hadn’t worked, but a proton beam from the Zeus … the probability was—

  The beam shot out from the ship, crossed space at light speed, and hit the artifact. Nothing happened. Fourteen seconds later, Orbital Object #7 hit the invisible outer edges of Space Tunnel #438. A Schwarzschild radius is not a probable number. It does not sometimes exist, sometimes not. The mass of Orbital Object #7, too great to go through the tunnel, was collapsed and imploded, but not before whatever it housed sent a massive wave effect in all directions as it had been designed to do, a final defense when its attacker was too great for any other. It was a simple matter of the equations, without unknown variables, without loopholes, without fudge factors. Without anomalies lying outside the energy barrier.

  Classical physics, not quantum physics, controlled the artifact’s end.

  The Faller warship, closer, caught the wave first. Syree saw it happen on the display. The enemy ship glowed, brighter and brighter, and then exploded like the trillions of tiny nuclear bombs it had become. The wave traveled at the speed of light, but as the destruction of Daniel Austen’s shuttle had shown, it was also subject to the inverse square law. The Zeus was much farther away than the Faller ship had been. Maybe, Syree thought, far enough away that the wave will have spent itself … or if at maximum force it actually affected elements with an atomic number lower than seventy-five …

  Her major regret was that she would, in all probability, never know what had really happened.

  From her comlink Gruber’s voice—that was his name, Gruber—said in disgust, “Ahmed, we cannot talk to them …”

  No, because we’re somewhere else, Syree thought, or will be, and actually felt her lips curve into a grin as the wave effect hit, so little diminished by distance that there was no perceptible lag before the Zeus exploded from selected nuclei outward and ceased to exist.

  The wave raced outward in all directions.

  Syree Johnson and her team of physicists had been right; at its lower settings, the wave effect from Orbital Object #7 obeyed the inverse square law. The weapon had been designed that way. Things that should be destroyed close up could therefore be taken care of, without undue damage to farther things that should not be destroyed.

  Full-strength setting, however, was another matter. Full-strength was only activated by meeting a force that could destroy the entire weapon itself, and anything that could do that was very dangerous indeed. It must also be destroyed, no matter how far away it might be.

  In fourteen minutes two seconds, the wave reached the nearest planet in the star system. Worlders, watching it wander through their sky, had named it Nimitri, “the sister blossom.” A bleak, frozen, atmosphereless globe of rock, Nimitri was rich in iridium and platinum, with unusually large amounts of thorium and uranium. The nuclei of these deposits, plus those of every other element with more than seventy-five protons in the nucleus, destabilized. They underwent substantial increases in the probability that each nucleus would emit a radioactive particle at any given time. Radioactive decay accelerated dramatically.

  When the phenomenon subsided, Nimitri was the most radioactive object in the system by a factor of twenty-nine—for the time being. However, there was no life on Nimitri to recognize this fact, or to be affected by it.

  The wave effect sped on toward World.

  TWENTY-NINE

  IN THE NEURY MOUNTAINS

  As the long afternoon wore on, Bazargan lay on the humans’ collective blankets just inside the cave, while Gruber and Ann sat apart, talking in low voices. Bazargan could make out no words. On reflection, he decided he was glad of this. If they were discussing the coming wave effect, he felt too weak to follow what would undoubtedly be multiple complicated speculations. If, on the other hand, the pair were talking personally, Bazargan didn’t want to hear.

  What he must think about was what to do after the wave effect struck. He was still the leader of this sorry expedition, after all. A leader mildly cooked by radiation, of an expedition with two dead children, one team member missing and crazy, and one kidnapped alien, also missing and, by now, possibly also driven crazy by either the Terran lunatic or her own biology.

  The ancient Persian poets didn’t write verse that covered this situation. Unless, of course, you chose to stretch a situation. Sadi, for instance:

  When the heart wanders, seeking endless change,

  And from its own safe solitude does range,

  Nor peace it finds, nor any virtue more …

  Certainly true enough! He’d left the safe solitude of academe for the field, and at the moment both peace and virtue seemed in very short supply.

  Or—another thought—perhaps he, Ahmed Bazargan, had just become too old for fieldwork. As every anthropologist eventually did.

  “Ahmed, what are you thinking?” asked Ann, the ever sensitive. Gruber looked around vaguely; undoubtedly in his theorizing he had forgotten that Bazargan was even there.

  Bazargan said, “I was just planning what we should do after the wave effect passes. If we’re still alive.”

  Gruber said, “We leave the mountains. Call the Zeus, find David, leave World, convince the authorities
on Earth to send a properly equipped expedition to dig out the buried artifact.”

  “You make it sound so simple, Dieter.”

  “Well, no, not simple …”

  Ann said, “We start by leaving the mountains, that much is true. Ahmed, you can’t go back the way we came. You are too sick.”

  And too afraid to repeat that tiny tunnel. Bazargan was grateful to her for not saying it aloud.

  “But,” Ann continued, “Dieter thinks we can find another route, based on his explorations yesterday. He will go first, scout it, and return for us.”

  “Fine,” Bazargan said. “But first—listen! The comlink!”

  Static spewed from the comlink, left out in the open beyond the lip of the cave. Bazargan staggered to his feet and, supported by Gruber, lurched into the darkening afternoon. Ann bent to scoop up the link and hand it to him.

  “Dr. Johnson? Dr. Johnson? What’s happening? Listen, please, we’ve made a discovery here, buried in the Neury Mountains …” First things first. Bazargan had no idea how long anyone at the other end would listen. “Dr. Gruber thinks it’s some sort of probability field, and may be linked to Tas … to the artifact you’re towing toward the space tunnel. Here is Dieter, he can explain much better than I …”

  Gruber seized the comlink. “Dr. Johnson, Dieter Gruber here. Are you there?”

  No answer.

  “Scheiss, what is wrong with me? They are an hour away at light speed, Ahmed, of course they don’t answer.”

  “A billion clicks,” Ann said, off to one side.

  Finally Gruber said in disgust, “Ahmed, we cannot talk to them. Only make a report.”

  “Well, then, do so. And afterward leave the link open.”

  Bazargan returned with the blankets inside the cave. Ann and Gruber stayed outside, under the open sky. Bazargan watched them pass the comlink back and forth, each explaining what had been noted, discovered, conjectured. Bazargan, through a haze of weakness, caught only the occasional word. Lagerfeld scan. Probability field. Neurotransmitter exocytosis. Buried artifact. Space tunnel, toroidal field, beta decay …

  Yes. He was too old for any more fieldwork.

  He drifted into the fitful, unsatisfying sleep of the ill. Gruber woke him, calling back from the lip of the cave, “Ahmed! Ahmed! Syree Johnson spoke on the comlink. She said, ‘Dr. Gruber, Syree Johnson here,’ and then stopped. She—”

  A roar: cataclysmic, explosive. It was so loud that the plastic comlink jumped on the valley floor. Bazargan heard the sound echo in the cave behind him, and a moment later echo again from the rock walls across the valley.

  Then silence.

  Finally Bazargan said quietly, “That was the Zeus, I think. All of them … dead …”

  Gruber said, “Get back farther in the cave. Now. The wave effect also travels at c.”

  The three of them scuttled backward. Bazargan tried not to think what might happen if the wave caused a planetquake and the cave collapsed. But wouldn’t that have happened simultaneously with the radio communication? No, Gruber had mentioned some sort of time lag …

  They sank to the floor and waited.

  Nothing happened.

  Ann said finally, “I don’t know what I expected, exactly … light, sound, action …”

  “Look here,” Gruber said. “My suit—all of our suits—they are not registering increased radiation. If the wave effect were really destabilizing everything with an atomic number above seventy-five, the trace radiation in these rocks should jump … but nothing. Nichts.”

  “What does that mean?” Ann said.

  “I must check my instruments.” He got to his feet.

  “Not yet,” Bazargan said sharply. “Your instruments are all outside. If there is a lag effect, you’ll be exposed. Wait here.”

  Reluctantly Gruber sat down again. Minutes passed. Finally he said, “Wait how long?”

  Ann giggled. Both men stared at her. “I’m sorry,” she said, sounding horrified at herself. “It’s awful, I know … but all I can think of is my mother warning us not to go in swimming for an hour after we eat lunch!”

  Bazargan’s mother had told him that, too. Despite himself, he smiled.

  “Well, I don’t wait an hour!” Gruber said.

  He didn’t. Gruber stood decisively, shot a warning glance at Bazargan, and strode out of the cave.

  In ten more minutes he was back. “I checked them all,” he said, and even in the gloom Bazargan could read the bewilderment on his ruddy face. “All the instruments, all over the valley. No radiation increase, not of any kind, even near a small deposit of thorium! No thermal increase, no nothing! The wave didn’t hit us!”

  Bazargan said, “Maybe it weakened too much before it reached here.”

  “Possibly. The inverse square law … but there is something else!”

  Ann said, “What, Dieter? You look … What is it?”

  “The instruments, they are time-tagged. An hour ago there was a seismic wave originating a quarter kilometer underneath the valley. Too weak for us to notice, but definite, and coming from the artifact. An hour ago!”

  Bazargan didn’t understand. “So?”

  “The seismic wave occurred exactly fifty-four minutes before Syree Johnson replied to us on comlink. Fifty-four minutes before the-explosion! Do you see what that means?”

  Bazargan, too weak to think clearly, didn’t see. It was Ann who said, “The wave reached us fifty-four minutes before we heard the Zeus explode. The sound of the explosion—and of Colonel Johnson speaking—traveled at light speed. But the seismic activity set off by the buried artifact—that happened the same moment that Tas exploded.”

  “Instantaneous,” Gruber agreed. “Ach, Ann, you do see—it means they were entangled! No space-time between them, like electrons in quantum entanglement. What it could mean … everything different from what we know. Everything changed.”

  “If it was an instantaneous increase in the probability field around World … But we have no idea how to be sure that’s what happened. We don’t even have any idea how to measure anything like a probability field. What units do you use? Not any ordinary ones. Your instruments showed nothing, except for a physical shifting of rock, and that’s certainly a side effect of what happened. Whatever it was!”

  “But then I cannot prove anything at all happened! Or that the buried artifact did anything!”

  “Maybe it didn’t. Maybe the seismic wave was coincidence.”

  “Coincidence! At the exact moment the Zeus blew up? No, no … the buried artifact was instantaneously affected when Tas exploded, or however it was destroyed. The buried artifact responded—it generated a probability field that neutralized any effect of the wave hitting World. Listen, Liebchen—radiation emission from nuclei is always a matter of probabilities. The emitted particle must tunnel through the energy barrier, and it can do that only because part of the probability field lies outside the barrier. So if the probability field blanketing World changed the probabilities of the wave-destabilizing nuclei … But I cannot prove any of this!”

  It was a wail of intellectual despair.

  Bazargan struggled to speak. “But we have one measure of the probability field … Ann said … the human brain.”

  Gruber said, “But my brain felt nothing different! Did yours? Yours!”

  Bazargan and Ann shook their heads. But then Ann said, “Not the human brain, Ahmed. We’re in the middle of this null zone in the field, remember? And our brain didn’t evolve in this probability field, anyway. That’s the whole point of why we can’t ‘share reality.’ We need to see the effect of the wave, if it came, on Worlders’ brains. On Enli.”

  “Yes!” Dieter said. “All right, Ahmed, can you travel? Let’s go!”

  Protest would be useless, Bazargan saw. And he wasn’t going to get any fitter to travel in the very near future, anyway. No point in delay.

  Ann said, “Shouldn’t you find an easier way out first, Dieter? Make the trip as easy on Ahmed as possible.�
��

  “I know an easy way,” Gruber said, unstoppable. “Mostly. Come on, Ahmed, I will carry you.”

  Bazargan got to his feet. He didn’t want Gruber to carry him. But by leaning on both the geologist and Ann, Bazargan could hobble along without too much discomfort. Out of the Neury Mountains.

  And into what? If the wave had affected the rest of World beyond Gruber’s null zone, then there might be widespread physical havoc. If the wave—or the probability field possibly defending against it—had affected Worlder brains … then who knew what they would find beyond the mountains?

  THIRTY

  GOFKIT RABLOE

  Having dispatched her fellow villagers to alert World, Azi Pek Laridor, servant of the First Flower, took Enli and Pek Allen to the village root cellar, which was communal, sturdy, and large. Enli had seen many like it in small farming villages. If larger villages ran out of food that could be preserved, Gofkit Rabloe was prepared to barter its surplus for “town sweets”: fine cloth, bicycles, glass vessels, flower remembrances.

  This root cellar was built into the side of a low hill. Azi pulled open the sloping wooden door. Most of the harvesters had gone as runners, but the old, young, and infirm were gathering up their necessary belongings to join Azi in the cellar. Enli saw them moving from the village square toward the hillside.

  “Faauggh,” Azi said. “Smells damp. We’ve had so much rain … But we build well, Enli. It’s not too uncomfortable.” She held up an oil lamp and led the way down, her gravid belly unbalancing her slightly on the three stone steps. The steps descended to a wooden platform that covered the entire floor, keeping it dry above the hard-packed dirt. The cellar smelled of loam and wood, mixed with the spicy lively odor of dried zeli fruit. Around the walls were crude wooden shelves packed with jars, crates, and vegetables. Wooden barrels dotted the floor, each marked with a family emblem. The barrels also served as tables for more oil lamps, which Azi lit, one by one. No attempt had been made to create beauty here; except for the round utilitarian barrels, all was straight lines and sharp angles. Yet there was a flower altar, to the right of the door.