PROBABILITY MOON

by Nancy Kress

  Enli pulled herself along the hard stone. She was an informant. Very well, she had informed herself. Gathered information and looked at it hard and there it was, unwelcome and inescapable as the decay of a flower.

  The Terrans were real.

  EIGHTEEN

  EN ROUTE TO SPACE TUNNEL #438

  Three days and two hours out toward the space tunnel. Two days and fifteen hours left to go.

  Syree had hardly slept, even though no glitch had developed in the arduous process of moving Orbital Object #7. They hadn’t yet covered even a third of the distance. Velocity had now reached two thousand six hundred klicks per second. Still Syree found herself silently urging—faster, faster —a pointless emotional exercise. The Zeus was delivering all the power she could.

  The ship had not shaken apart, although she was severely strained. If she could keep it up for another two days and fifteen hours, they could cut power and let inertia carry Orbital Object #7 through the space tunnel at 4,873 clicks per second.

  If, of course, Orbital Object #7 would go through at all.

  Syree had, for lack of anything else to do, run the equations dozens of ways, with dozens of variables, hopeful estimates, downright fudge factors. If the capacity of this particular space tunnel varied by only three percent from all the other space tunnels … if the standard capacity estimate by Martian engineers was off by only two percent … if the mass of the artifact was four percent less than they’d determined …

  None of it made any real difference. Any mass had an associated Schwarzschild radius, defined as the radius below which, if you squeezed the object enough, it would become a black hole. That was what had happened to the Anaconda fifty-three years ago. It was what would happen to the artifact as well. Unless the equations had a loophole in them that human physicists didn’t know about.

  Loopholes existed. Otherwise, the Fallers could not have constructed their wave-phase alterer. And humans knew so very little about the artifact, which had been constructed by the same vanished beings who had created the space tunnels. Probably. So maybe it was possible that Orbital Object #7 would go through Entrypoint #438 when another object of equal mass but different origin would be compressed to a tiny black hole.

  But not according to the equations.

  At least if Orbital Object #7 was destroyed, the Fallers wouldn’t get it. And there was that small chance of an unaccounted-for variable that would send the artifact careening out the other side.

  “Communication signal from the Hermes, sir,” said Lee, seated in front, of his displays on the bridge.

  “Play communication,” Peres said. Everyone on the bridge paused to listen.

  The Hermes, the Zeus’s tiny flyer, should be rapidly approaching the tunnel, eight hundred and fifty million clicks ahead of the Zeus. The flyer pilot, Lieutenant Amalie Schuyler, had been punishing herself with far too many gees in order to reach the tunnel this far in advance of the parent ship. Whatever she had to say had been forty-seven minutes getting to the Zeus.

  “Hello, Commander,” she said, and Syree recognized in Lieutenant Schuyler’s labored voice the sound of a human body that could not take much more. “By the time you get this, I should be through the tunnel. It’s less than a minute ahead of me now. No problems with the flight, no sign of the enemy. Instructions for Caligula Command understood and unchanged. Good luck to you all back there. Out.”

  Lee grinned at Syree. So far, so good. And by now Amalie was safe in human-held Caligula space, beyond the tunnel. Caligula system was a military outpost; it kept a manned flyer in constant orbit around its side of the space tunnel. Lieutenant Schuyler would report to the flyer pilot, who would then relay the information to Caligula Command in plenty of time to act on it.

  “All plans in order,” Peres said to the bridge at large. His voice held less satisfaction than Amalie Schuyler’s. The Zeus’s part of “all plans” was considerably more ambiguous than was the Hermes’.

  By flying through Space Tunnel #438, the Hermes had assured that the next tunnel-virgin object would also materialize in Caligula space. That might be the artifact, but neither Syree nor Peres really believed it. The Fallers understood the habits of space tunnels as well as humans did (maybe better, given the new wave-phase alterer). Sooner or later—probably sooner—a Faller craft would emerge from the space tunnel. It would then go back through, so that whatever sailed into the tunnel after it would end up in Faller, not human, space.

  The Hermes carried orders designed to keep that from happening. Syree had calculated the Zeus-cum-artifact’s velocity, time, and distance out to the eighth decimal. If nothing disturbed the towing operation, the artifact would zoom into Space Tunnel #438 two days, fifteen hours, fifty-seven minutes, and three seconds from now, at 14: 37 hours ship time. Five minutes before that, per Lieutenant Schuyler’s instructions, a flyer would dart from Caligula space into the tunnel, to emerge in this star system. It would then immediately dart back, “paving” the way for the artifact to follow it.

  The Fallers might well anticipate this maneuver, of course. They had proven good strategists in the past. Thus, a second human flyer would also dart in and out from Caligula space four minutes after the first one, and only sixty seconds before the artifact reached the tunnel.

  “Sixty seconds?” Peres had said, when Syree showed him her calculations. “Can we cut it that close, Colonel?”

  “Yes,” Syree said, with more confidence than she felt. The numbers were solid, but reality had a way of intruding variables not in the numbers. She did not say this.

  “So we detach the artifact at the last minute,” Peres had said, “and it goes through into Caligula space. Then what?”

  But to that, there had been no real answer. Lieutenant Schuyler had been briefed to warn Caligula Command that they might receive an invaluable alien weapon. Or a tiny black hole, perhaps traveling at 4,873 clicks per second. Or a powerful wave that destabilized nuclei of elements with an atomic number above seventy-five. Or nothing at all.

  Meanwhile, key officers lived on the bridge, sleeping in chairs, unwashed and unsmiling. And all the while the great gray sphere filled the viewscreen, blotting out the stars.

  “Lunch, sir.” A soldier from the galley crew, carrying a large covered tray. Hot fragrant odors drifted through the bridge. The crewman set down the tray and uncovered it.

  “Thank you,” Peres said. “Dismissed.”

  Lee picked up a hot sandwich and took a big bite. Syree made herself eat another one. She couldn’t have told what it was, except fuel.

  Major Ombatu, whose spirits had evidently not been lifted by the Hermes message, said irritably, “I can’t eat with that smell in here. Somebody needs to wash.”

  “Shut up, Ombatu.”

  “Don’t,” Ombatu said evenly, “tell me what to do, Lee.”

  They looked at each other in contempt, the pointless contempt of people together too long, under too great a strain, who nonetheless needed each other. Everyone needed to wash. No one wanted to leave the bridge long enough, even though nothing untoward had happened.

  And then, seven hours later, it did.

  Executive Officer Debra Puchalla had the conn. She said to Peres, who was lying down but not sleeping on a recliner in a corner of the bridge, “Sir! Object has just emerged from Space Tunnel #438 … getting a signature … it’s a skeeter.”

  “Fallers,” Peres said. “Direction?”

  “Toward us … wait … second object emerged. Getting a signature … a Faller warship.”

  Peres and Syree both moved to the displays. The two enemy crafts, dots on a screen, were diverging. The skeeter hung motionless near the space tunnel, ready to dart back through. The warship began to move toward the Zeus. Undoubtedly the Fallers had identified the Zeus’s signature and had found it (surprise!) to have increased in mass by a factor of nineteen. The enemy now knew what the humans were doing. Their next step would be to prevent the Zeus from doing it.

  “Commander,” Puchal
la said, “change in enemy direction. Skeeter is retreating … moving closer to the space tunnel … there, she’s gone through.”

  “Heading back to Faller space to report,” Peres said. Of course, Syree knew that what he’d meant to say was that the skeeter had already disappeared into the tunnel forty-three minutes ago. All their information was old, limited by c. As the space tunnels themselves somehow were not.

  Puchalla said, “Enemy warship advancing. Enemy acceleration is two gee … present distance seven hundred eighty million and—”

  “Turn off ship drive,” Peres said.

  Syree said swiftly, “Wait, Commander.” The Zeus was an ant laboring along under a carefully balanced cantaloupe, but she couldn’t allow the cantaloupe to be dropped just yet. “One moment, please!”

  “Belay that last,” Peres said to Puchalla. He swiveled to fully face Syree. “Dr. Johnson?”

  The title said volumes; Peres was reminding her she was a project specialist here, not a line officer. She nodded. “Commander, I would guess you want to turn off the drive and detach the artifact. Let it sail on its trajectory to the space tunnel without us, so the Zeus is free to fight. But if you detach now, the artifact will be traveling at … just one moment …”

  Furiously she keyed in the data, ran the equation. “If you detach now, the artifact will continue at our present velocity, two thousand eight hundred sixty clicks per second. Instead of the four thousand eight hundred seventy-three it will reach if the Zeus continues to accelerate it. At the reduced speed, the artifact will take another … just a second … another four days, fifteen hours to get to space tunnel. But if we can keep accelerating it as long as possible, we can cut the time it will take by a multiple factor.”

  “Dr. Johnson, we’re under attack!”

  “Not yet. The skeeter has gone. And when we get within the warship’s firing range—even allowing for a comfortable margin for the unknown—we can detach the artifact. Just not yet. Even one more hour of acceleration will boost its velocity by another thirty-six clicks per second. With ten hours, we could get it up to three thousand two hundred sixteen clicks a second. And still give us time to detach and maneuver. To detonate, if that’s what you choose.”

  Peres was silent. Considering? Syree rushed on.

  “And remember, our flyers will come through at the designated time. The smaller the time interval between our flyers’ appearances and the artifact’s hitting the tunnel, the less chance of another Faller craft emerging and diverting the artifact to enemy space. To keep that time interval short, we have to keep accelerating the artifact as long as possible.”

  Peres scowled. “Do you really think the Fallers, now that they’re here, will allow that to happen? They’ll fire on the artifact just before it goes into the space tunnel, if they have to. They’ll blow it up.”

  “They might try. But we don’t really know what will happen between now and then. Until we do, continuing to accelerate the artifact loses us nothing and gains us shortened time for the Fallers to do anything more to us. And if we’re attached to the artifact, and they want it, they’re less likely to attack us, at least until we’re much closer to the space tunnel and they see they have no choice. And at that point, of course, we’ve also moved the detonators on the artifact a lot closer to the enemy ship.”

  Peres looked thoughtful. “If we detonate just minutes before the artifact reaches the space tunnel … if we do that, can we get the Faller ship in the same detonation?”

  “Depends on how close they stay to the space tunnel. But it’s at least a possibility. One we don’t have if we detach and detonate now.”

  Peres considered. Syree held her breath.

  “All right,” he finally said. “We’ll continue acceleration. For now, anyway. Unless the situation changes.”

  “Thank you, sir,” Syree said, swallowing her pride. His decision, and she knew she must acknowledge that or risk looking like someone trying to jump the chain of command.

  “Helsman, continue course and acceleration.”

  “Continuing acceleration.”

  “Ms. Puchalla, arm all weapon systems. Crew to battle stations.”

  “All weapon systems arming.”

  The Zeus was a retrofitted military cruiser, supposedly on a scientific mission. Syree doubted that under any circumstances could her weapons match those of a Faller warship. But right now her attention was fastened on Orbital Object #7. She had saved it, at least for some unknown stretch of time. Throughout the Zeus, battle-station Klaxons sounded.

  “Weapon status.”

  “All weapon systems armed and ready. Enemy speed change … wait … he’s decelerating, Commander … hard deceleration … stationary position. Enemy position: two hundred clicks from Space Tunnel #438, ninety degrees lateral to trajectory of artifact.”

  Almost eight hundred million kilometers apart, the two ships tracked each other. Their data was forty-three minutes old, but it served for cat-and-mouse. The cat stationary by the hole, the mouse moving faster and faster. And carrying a cantaloupe. Syree repressed her own mental image; Grandmother Emily would not have approved.

  Peres said, “Dr. Johnson, calculate time and position of detonation of the artifact for maximum effect on the Faller warship, assuming it does not change position, and also assuming the artifact continues to be accelerated by the Zeus until we’re a hundred clicks outside known enemy firing range.”

  “Yes, sir.” Syree began the calculations.

  Keep moving. One of the oldest of military dicta. Keep moving, stay out of easy range of the enemy, be prepared for changes in the enemy’s tactics.

  But in this case, Syree thought, the enemy had no reason to change tactics. Unless they suspected the artifact was rigged to detonate, which they might or might not suspect. If they did, probably they would let the artifact get only so close to the space tunnel before they attacked. But how close was that?

  No way to know until the Faller ship moved.

  And until it did, Orbital Object #7, formerly the planetary moon Tas, continued to be shoved along through space. Still intact, and still up for grabs.

  NINETEEN

  IN THE NEURY MOUNTAINS

  The rock closed around him, suffocating him.

  Bazargan could feel it in his throat, his lungs. He couldn’t breathe. The cold smell of damp stone choked him, as all around him the relentless rock crushed his body to pulp …

  Bazargan squeezed his eyes shut and stopped wriggling forward. He couldn’t do this. Already his shoulders touched both rough sides of the tunnel, and ahead the passage grew even narrower. He couldn’t do this. Rock was choking him, crushing him, and he would die here. He couldn’t make himself move forward. Wave after wave of nausea swept him, and his heart hammered so hard it felt close to bursting. Sweat, unnaturally cold, streamed into his eyes.

  He couldn’t do this. He was going into shock, and he would die here.

  Frantically he stabbed through his mind, looking for something—anything—to save himself. Could thoughts stop your body from going into shock? He had no neuropharms to stave off shock, he seldom used neuropharms, it was people like David Allen who relied on them. Americans, used to the easy, the luxurious. He was Iranian, he didn’t need neuropharms, he needed …

  What? He was going to die here. He couldn’t do this.

  Something—anything—to grasp on to—

  Give never the wine bowl from thy hand,/ Nor loose thy grasp on the rose’s stem …

  The rose’s stem! Behind closed eyelids Bazargan pictured that stem, reached for it with cold fingers scrabbling on cold rock.

  He couldn’t remember the rest of the poem. Hafiz, the greatest of the Persian lyric poets, and Bazargan couldn’t remember the poem. But the rose itself was still there, hold the rose … There were other poems …

  How sweet the gale of morning breathes!l Sweet news of my delight he brings …

  Breathe in the gale of morning. Fresh air, sweet, smelling of flowers and dew �
��

  News that the rose will soon approachl the tuneful bird of night he brings—

  Hold the rose. Smell it, stroke the silky petal, hear the nightingale sing high and sharp and sweet.

  Ahmed Bazargan’s heart slowed, a small slowing, but perceptible. The clammy coldness pressing on his body eased slightly. He was not in a crushing tunnel with tons of rock above him, he was in a morning garden. Birds sang. Roses released clouds of scent as he bent over them.

  … odor to the rose-bud’s veil, and jasmine’s mantle white, he brings …

  Jasmine. Yes. The long slender leaves, the white fragrant flowers.

  Bazargan advanced through the garden. Leisurely, drinking in every morning moment, every scent and smell and sound. Pomegranate, rose, jasmine, almond. The garden sown of poetry was the most vivid and solid he had ever known, each drop of dew etched in crystal, every petal glowing with bright color. He advanced through this garden picking the flowers, holding them with warm living fingers: Mind the thorns, place the white lilies beside the red roses and savor the velvety contrast, breathe deeply of the glorious perfumes …

  With every fiber of his being, blind to any other reality, Ahmed Bazargan created the garden. And got himself through the tunnel.

  “Ahmed! Ahmed!”

  Slowly he came to. He sat with his back to stone. Ann bent over him, a small metal instrument at his heart. Behind her crowded Dieter and David and Enli. David’s tunic was torn to shreds and blood smeared his shoulders. Of course—he had scraped through that narrow space without a suit.