Probability Sun

by Nancy Kress

  Katrina’s body was strapped into a small two-person personal flyer, of the kind that rich people and commercial explorers used. In the pilot seat was strapped the body of a young soldier who had died that same day of a brain virus, one of the virulent strains that demolished entire cerebral centers in hours. The flyer was loaded with provisions, including toys and holos suitable for a four-year-old girl. Except for the usual civilian light arms, the craft was defenseless.

  The computer, preset, flew it through Space Tunnel #473, shut down all engines, and let the flyer drift in space.

  McChesney and his team waited on the other side of the tunnel. They were effectively blind. No probe could go with the flyer, no signal could be sent back; the Solar Alliance had ample evidence that the Fallers were well able to detect anything electromagnetic. Their detection technology seemed to be equal to humans’. So did their weaponry. And their defenses, since they’d acquired the mysterious beam-disrupter shields, were infinitely superior. A proton beam fired at a Faller skeeter, the equivalent of a human flyer, simply disappeared. No scientists had been able to discover where the beam went, or why the conservation of matter/energy had not been violated. McChesney didn’t concern himself with the physics problems, which he knew he wouldn’t understand.

  He didn’t understand nanotechnology, either, but the science advisors told him that might be the one area in which humans were ahead of Fallers. No one knew for sure. No Faller had ever been captured alive, and no skeeter had ever been taken as anything other than a melted hulk unsuitable for reverse engineering. However, neither the charred dead Faller bodies nor the charred dead Faller craft had shown, as far as the science advisors could guess, any signs of nanotech.

  “How long?” McChesney said, on the human side of Space Tunnel #473, although of course he knew the answer.

  “Forty-seven E-hours,” said his aide.

  “Fuck it. We’re going in.”

  The aide stared at him. “Supposed to be two more hours, sir.”

  “Now.” And then, by way of feeble explanation, “It feels right. Now!”

  “Yes, sir,” the aide said, her voice expressive of reservation, and they had gone in.

  And hit the goddamned jackpot. Caught the Fallies un-fucking-believably in the act. Actually aboard the human flyer.

  Wait forty-nine hours, the intelligence guys had said. We know that Fallers often wait twenty E-hours from the point of detection to the point of action. Their home planet has a twenty-hour day; maybe there’s a hard-wired circadian rhythm that affects social decision making. Maybe not. At any rate, it’s definitely nine hours up to the tunnel from the surface of their colony planet, given the planet’s position when you send the flyer through, and given the speed of their civilian skeeters. We’re assuming they have no military craft in the colony. No telling how long it will take them to notice the drifting flyer. They might even detect our flyer the second you send it through the tunnel, if they have a probe in orbit around the space tunnel.

  “Then why didn’t the probe detect our original flyer?” McChesney asked.

  “Maybe it did. Or maybe there’s no probe because this is such a small colony and not military. We’re flying blind here, Colonel. Just go in at forty-nine hours and see what you catch. Twenty hours from the time they detect the flyer to decision to go up. Nine hours up. Another twenty hours to contemplate the flyer and probe it with sensors. Then you go in.”

  But McChesney had gone in two hours early, and caught the bastards in the act.

  The colony skeeter had matched trajectory with the drifting human flyer, five clicks away, when McChesney’s first military flyer erupted from the space tunnel. The skeeter was better armed than humans had expected. It opened fire immediately on the flyer and destroyed it. But McChesney had four other flyers and a warship. He blasted the skeeter before it could annihilate anything else. The skeeter, unequipped with the new Faller shields that could render a particle beam useless, exploded.

  The warship carried the most advanced sensors humans could devise. They picked up the two heat signatures inside the drifting flyer, where only two unheated dead bodies should have been. The sensors also registered that the heat signatures were not moving.

  McChesney moved faster than safety regulations permitted. In seven minutes he had suited Marines aboard the flyer. The Marines were unnecessary. For once, the science brains had actually understood a military situation.

  The Fallers had undoubtedly subjected the drifting human flyer to every sensing device they could before they boarded her. Their sensors told them there were two dead humans aboard, one a child. Maybe the Fallers had been able to tell that the man was damaged in the brain, a father who had abruptly died while taking his child somewhere. Maybe not. Maybe they had been able to tell that Katrina Van Rynn’s body included broken and reset bones. Maybe not. But they had never, to human knowledge, had the chance to examine a human child. Their blitzkrieg approach to attack had not included taking prisoners. They had taken possession of dead adult soldiers before now—but never a child. An alien species would want to know how their enemy developed—wouldn’t they? And they would reason that this probably wasn’t a military craft, not with a child aboard. Surely the Fallers had learned by now that humans did not take their offspring to battle. Katrina Van Rynn in her helpless, utterly threatless flyer, had been good bait.

  A single Faller had boarded, accompanied by a robot probe capable of detecting any trap known to Faller technology. It couldn’t, however, detect the unknown. If the boarding Faller had stopped breathing, it would probably have blown up the Faller, the ship, and itself. It would probably have done the same if its master had told it to, or if the Faller’s suit had signified any breach, or if any machinery aboard the flyer had suddenly activated.

  None of those things happened. The tiny nanos that the robot probe didn’t know how to detect clung to the bottom of the Faller’s suit as soon as he crossed the threshold. The nanos never punctured the suit. Instead they moved through it, one molecular layer at a time, mindlessly destroying a molecule and then immediately rebuilding it behind them out of the same atoms, as they had been programmed to do. Neither robot nor Faller detected a breach because there never was one. When the nanos reached material giving out the heat signature of living flesh, their program changed.

  The nanos entered the Faller body and began to paralyze it slowly. Human biologists had learned enough from the few badly charred Faller bodies they’d salvaged to analyze the genome. It wasn’t DNA-based. Thus, almost anything biological added to it could be fatal. But nanos weren’t biologics; they were tiny machines. Their programming determined easily what gas the Faller breathed inside his sealed suit: the species’ medium for energy transport. Then they began to absorb the supply of it, replicating rapidly at the same time. The Faller, never realizing it, slid easily into the equivalent of oxygen-deprivation (it wasn’t oxygen) and fainted. Or perhaps fell asleep, or whatever the alien equivalent was of reduced conscious activity. The nanos stopped replicating. They kept the Faller unconscious but did not deprive his brain of all energy. The probe did not register anything wrong; every complex species sleeps.

  By the time the Marines entered the ship, the probe couldn’t register anything. Other nanos it had never been built to detect had inactivated it, atom by atom.

  The Marines carefully bound the sleeping Faller’s limbs and carried him, suited, to the warship. McChesney immediately took off through Space Tunnel #473, followed by twelve other tunnels, some of them highly fluid. There was no way he could be followed. Xenobiologists aboard ship began careful analysis of the gas mixture inside the Faller’s suit before they removed it, as well as every other variable they could think of. By the time they let the alien wake up, their knowledge of Faller biology, until now minuscule, had increased by orders of magnitude.

  The alien awoke inside an environment, constructed to his exact biological needs. Atmosphere, humidity, temperature, all matched what had been inside his
suit. He also woke bound to the back wall, gently but inexorably. Small capsules had been removed from various parts of his body. Maybe they were the equivalent of tooth fillings, but maybe not. McChesney and his medical team were not going to allow the first Faller POW ever to turn suicide.

  Nor were they going to let him starve himself to death. The xenobiologists weren’t exactly sure what liquids would nourish the alien, but they’d analyzed the contents of his stomachs (two) and put together what they hoped were reasonable synthetics. The synthetics would be delivered by forced feeding tube. By the time the prisoner regained consciousness, his only options in his padded prison were to communicate or not.

  By that time, McChesney’s warship was in World’s remote star system, ready to transfer cell, prisoner, and xenobiologists to the Alan B. Shepard. After the transfer, McChesney flew back to Space Tunnel #438 to take up position in orbit around it until further orders. The warship carried every weapon known to human military. Nothing was coming through Tunnel #438 and advancing toward World without going through McChesney.

  The Fallers may or may not have realized that one of their own, instead of dying with the colony skeeter, had been captured alive. But if they did, they weren’t getting him back.

  * * *

  “Tell me again,” Marbet Grant said to Lyle Kaufman as they waited at the security checkpoint in the deep gut of the Alan B. Shepard. She closed her eyes.

  Watching her, Kaufman understood. It wasn’t that Marbet wanted to hear the information again because she hadn’t understood it. She wanted to hear it again as a mantra, a calming device, a stream of known words. After this last checkpoint, nothing would be known.

  He said, “The theory—and it is only theory—is that the Fallers have a strong, overriding instinct to eliminate any ‘others’ that could present any danger to themselves. It’s an evolutionary strategy that may have worked and been reinforced over eons on their home planet, which we know has high cosmic bombardment and thus may have yielded many, many mutations. They simply wiped out anything, including their own children, that were too different.

  “At the first sign of any otherness, a Faller seems to go into something like human instinctive fear of falling—a xenophobia way beyond what humans usually feel. Although nobody is sure, there may be only one surviving, genetically similar group of Fallers. No races, few permitted variant alleles. Anything else arouses hostility, including us.”

  “The ultimate committers of hate crimes,” Marbet murmured. She still had not opened her eyes. After a moment she added, “I’ve never met any alien.”

  He shouldn’t be surprised, Kaufman thought. She’d never been out of the Solar System, and no other aliens in the known galaxy except Fallers had invented space travel. Or even the steam engine.

  “All right,” Marbet said, opening her eyes, “I’m ready.”

  Kaufman thumbed open the door.

  The Faller’s cage was ten meters wide by twenty meters long. The length was divided by an invisible, two-molecule-thick plastic sheet separating the Faller’s atmosphere from the human one. The barrier conducted sound almost perfectly. Behind it the Faller was bound naked against the far wall, which was padded so that the alien could not injure itself, no matter what it did.

  Not “it,” Kaufman reminded himself. The xenobiologists, none of whom at Marbet’s request were present, had decided that the Faller was male, although not for any reason apparent to Kaufman. The alien was about a meter and a half tall, covered with hairless tough hide of deep brown. Short powerful legs. An equally powerful tail on which he balanced at rest. A torso like a barrel, with three incongruously slim “arms” that seemed all flexible tentacle, each ending in a hand with three fingers and an opposable thumb. No claws or nails. The head, although roughly the size of a human head, was far more cylindrical. Two eyes, no visible nostrils (they were located under the chin), a large mouth.

  At first sight of them, the Faller bared sharp long teeth.

  Marbet did not react. She walked to the barrier and sat down cross-legged in front of it, looking upward at the alien. A posture of submission, Kaufman decided, and wondered if that was a good idea with a species that wiped out anything it didn’t like.

  “You can leave if you like, Lyle,” Marbet said over her shoulder. “I’m going to be here for a few days, and there won’t be anything to see.”

  A few days? “You mean … sleeping and eating here?”

  “Yes. And I’ll need a chamber pot.” And then, not rising, Marbet began removing her clothes.

  “Do you … do you want me to take those away?”

  “No. Leave them right here, along with everything else you bring me. Food, utensils, bedding. Also an erasable tablet and pen—not a computer or holostage, please—and a music cube.”

  “All right,” Kaufman said. Marbet was now removing her underclothes. Her body, genemod perfect, gave Kaufman a sudden lamentable erection. The alien was still baring its teeth. Kaufman left to find the things Marbet wanted.

  When he returned, he had controlled himself again. He laid the things beside her and then seated himself, cross-legged like her, against the back wall of the room.

  Marbet drew squares on the tablet, then laid it beside her in easy view of the Faller, who did not react. Although how could you tell? Maybe it was reacting all over the place, Kaufman craned his neck to see the tablet:

  Primes. Well, that made sense: The one thing in common between humans and Fallers was the space tunnels, which were marked in primes. Although the tunnels, inexplicably, included “one” along with the primes. Kaufman would have to remember to remind Marbet of that.

  Marbet held up both hands, fingers splayed. She held up one finger, waited. Two fingers, waited. Three fingers, waited. Five. Seven. Eleven.

  The alien did nothing.

  Marbet repeated the pantomime several times, got no response, then stopped. After that she just sat, watching.

  An hour passed. Somewhere in it, the alien stopped baring his teeth, perhaps because his facial muscles got tired. He did nothing else. Neither did Marbet, except watch.

  Eventually, to Kaufman’s surprise, she curled up naked on the floor and went to sleep.

  He watched her a while. She was so lovely. But watching even a beautiful woman sleep, and an alien do nothing, could only hold his attention so long. Kaufman left. It was all being recorded anyway, with flag programs to alert him to anything interesting.

  Kaufman felt pessimistic as he went to report by comlink to McChesney, now en route to the space tunnel. No response to something as basic as primes. How were they ever supposed to wrest from this enemy any knowledge as complex as the physics of the beam-disrupter shield? It seemed hopeless.

  Maybe Gruber’s buried artifact would somehow help. Tomorrow they would make orbit around World.

  SEVEN

  WORLD

  I don’t want to go down to the stupid planet,” Sudie said. She stuck her lip out at her father. “I want to stay on the ship with Marbet.”

  “Where is Marbet, anyway?” Amanda said. “I haven’t seen her for two days, and she promised to help me with my math.”

  “Life is a vale of tears,” Tom Capelo said. “Why don’t you ask me to help with your math? I’m a world-renowned physicist, after all, available to you at one-half my usual price.”

  “You don’t explain things clearly,” Amanda said.

  “Yeah,” Sudie echoed. “We want Marbet.”

  Capelo pushed back his irritation. He couldn’t afford it, not today. He needed all his concentration for the job ahead. He looked at his daughters. God, they were so beautiful. Amanda, with her mother’s blonde calm. And Sudie, a miniature of himself, now working up to what he had to ruefully admit could be a Tom Capelo tantrum if it weren’t squashed now. He tried again.

  “Sudie, Jane is going down to the planet with us.” And where was Jane? She was supposed to be getting the girls ready. Sudie’s hair was still a snarl, Amanda’s bag stood open but unpacked. Now
Capelo had an appropriate outlet for his irritation. “Jane!”

  “Don’t bellow, Daddy,” Amanda said. “Jane’s in the toilet.”

  “I’m not going down to that stupid old planet!” Sudie said. “I’m not! I want Marbet!”

  “Jane!”

  Jane Shaw came out of the bathroom. Capelo was even more annoyed to see that her short gray hair was neatly combed, her coverall spotless. While Sudie sat in a dejected tearful untended lump. He repressed this annoyance. Jane was a treasure, the one tutor-cum-nanny who had not quit within one month of being hired, and Capelo needed her too much to rile her.

  “Jane, we have insurrection. We have mutiny. We have limp pajamas, and I have to be in shuttle bay in five minutes, all of us leaving in forty-five. I am clay in your digits.”

  “Go on, Tom,” Jane said. “We’ll be there on time. You just go.”

  “May your blossoms bloom forever,” Capelo said, and Amanda smiled. They had all been reviewing the datacubes on World culture, but only Amanda had been truly interested. Sudie had not. She started to wail again, “I don’t want to go to the planet! I want Marbet!”

  “Isaac Newton never had to put up with this,” Capelo said, and escaped.

  Two corridors away, he turned back. A passing crewman flattened herself against the wall. Capelo barely saw her. He yanked open the door to the girls’ quarters. Poor Sudie, poor baby, she’d been through so much already, her little tearful face …

  Sudie sat on the floor watching a holoshow, laughing at the antics of a green hippopotamus and packing her toys into a plastic case. Her hair bounced in neat shining ponytails. Jane, helping Amanda pack, smiled at him and made a go-away gesture.

  Meekly Capelo closed the door and went to shuttle bay.

  * * *

  Sergeant Karim Safir, Specialist First Class, SADA, stood with Dieter Gruber, studying the flimsies of the Neury Mountains. Capelo hadn’t had much contact with the tech specialist, who had bunked and eaten with the crew and who had not, until now, been made aware of his duties beyond being told that there were caves to explore on a hew planet. Presumably Safir was used to such assignments. He was supposed to be the best Army spelunker on several worlds.