The Year's Best Science Fiction: Fifteenth Annual Collection

by Gardner Dozois

  Marc said, "The metals, that's why I'm here. They'll be more important than life, in the long run."

  Piotr: "I disagree. The asteroid belt is where we will go for metals. Mars is where we build a base to mine the asteroids. Going to be much cheaper to boost from here than anyplace else."

  Raoul appeared from the pint-sized galley toting a bulb of coffee. "So we've just wasted our time looking for metals on Mars? Suits me. If we jettisoned all of the damned ore samples there'd even be room to breathe on the return." Ann said, "We shouldn't be limited by what we think we know. Or what we think we're going to find. A biologist named Lovelock pointed out before the Viking landings that there was probably no life because the atmosphere was in chemical equilibrium with the surface. Spectroscopy from Earth showed plainly that there was nothing in it but boring CO, and nitrogen."

  "Good argument, you have to admit," Marc said.

  "But it assumed life would use the atmosphere as its buffering chemical medium. Unlikely, because it's so thin ... "That's what we found." Marc looked puzzled. They were coauthors on the microbial Nature paper, but they all knew the major work was hers.

  "Other life may have many ways of holding on deep underground. We can't reach it except through the vents."

  When her news of life was beamed to Earth, the public had chewed over it, and decided that it was not all that exciting. Just a bunch of microbes, after all. The deeper issue of its relationship to Earth life had to wait until they got the samples home. Until then, the issue was the province of learned talking heads chewing over the implications. Time for that later.

  They had been through all of this before, of course. In the course of two years you get to know each other's views pretty damn well, she reflected, and Raoul had his set look, jaw solid and eyes narrowed, already announcing his position.

  The second liftoff trial was grim. Their lives were riding on the plume of scalding exhaust. She fidgeted with the microcams-Earthside wanted four viewpoints, supposedly for engineering evaluation, but mostly to sell spectacular footage, she was sure. "Let's go," Raoul called in a husky whisper.

  The vehicle rose on a column of milky steam. The methane-oxygen burn looked smooth and powerful and her heart thudded as the ship rose into the burnt-blue sky. It was throttled down nicely, standing on its spewing spire as Raoul and Piotr made it hover, then drift sideways, then back.

  "All nominal," Piotr said, clipped and tight.

  "Control A 16 and B 14 integrated," Raoul answered. "Let's set her down."

  And down they came, settling on the compressed column. The ship landed within 10 meters of the damp smear that marked the takeoff.

  "Throttle down," came from Piotr in a matter-of-fact voice she did not believe for a minute.

  Then she was running across the rocky ground, feet crunching, her cheers echoing in her helmet along with all the others, tinny over the com.

  Celebration. Extra rations; they even ate the last Ego Bar. Joyful calls from Earth. The laconic way Piotr told the Airbus people that they would not be needing a ride home after all ... Then the next morning. Assessment.

  Now they had five days until liftoff and it stretched like forever. The rush to do the second test had kept them at it 16 hours a day, pouring their anxious energy into the other preflight procedures. After two years they functioned smoothly together, anticipating one another's needs wordlessly. The efficiency of true teamwork bore fruit: Now they were ahead of schedule. Ann worked alongside them and judged their mood and dreamed her own dreams. Home!

  The call of it was an ache in the heart. The cool green hills of Earth ... Still, she could not let go her own itchy ideas. She lay beside Piotr in the cold darkness and thought.

  Leaving Mars ... Behind her she felt the yearning of millions, of a whole civilization reaching out. Why had the issue of life here come to loom so large in the contemporary mind? It dominated all discussions and drove the whole prize-money system. Piotr and Raoul thought economic payoffs would be the key to the future of Mars, but they were engineers, bottom-line men, remorselessly practical. Just the sort you wanted along when a rocket had to work, but unreliable prophets.

  She suspected that the biologists were themselves to blame. Two centuries before they had started tinkering with the ideas of Adam Smith and Thomas Maithus, drawing the analogy between markets and nature red in tooth and claw. The dread specter of Mechanism had entered into Life, and would never be banished after Darwin and Wallace's triumphal march across the theological thinking of millennia. God died in the minds of the intellectuals, and grew a rather sickly pallor even among the mildly educated.

  All good science, to be sure, but the biologists left humanity without angels or spirits or any important Other to talk to. Somehow our intimate connection to the animals, especially the whales and chimps and porpoises, did not fill the bill. We needed something bigger.

  So in a restless, unspoken craving, the scientific class reached out-through the space program, through the radio listeners of the Search for Extraterrestrial Life-for evidence to staunch the wound of loneliness. That was why their discovery of microbes satisfied no one, not even Ann. Mars had fought an epic struggle over billions of years, against the blunt forces of cold and desiccation, betrayed by inexorable laws of gravitation, chemistry and thermodynamics. Had life climbed up against such odds, done more than hold on? To Ann, survival of even bacteria in such a hellish dry cold was a miracle. But she had to admit, it left an abyss of sadness even in her. And there was still time ... Morning. Four days to go. Over breakfast Ann signaled to Marc, took a deep breath, and made her pitch. The last few days' hectic work had pushed them hard. More than that, it had nudged them across an unseen boundary in their feelings toward the trip. Despite what Marc and Raoul had said about returning, they all realized that this was a one-time experience. Once they left it would be all over.

  Raoul looked up. "The vent trip again? I thought we laid that to rest. You didn't find anything the first time."

  "Absence of evidence is not evidence of absence," she shot back. Raoul frowned, "Besides, there isn't time. We're not packed up yet."

  "We're ahead of schedule," said Ann. Piotr cut in quickly. "Under normal circumstances, yes." He gestured at his cast. "With this, I'm clumsy. It takes longer to do everything." He looked at Ann. "I need your help."

  They all knew that a public admission of weakness cost him a lot, and it touched her, but she was determined not to be swayed. She refused to meet his eyes. Damn. Why did women always have to choose? He never would've asked that of a man.

  In an impassioned tone, she used her Columbus argument-how could they go home when there was the chance they had only nibbled at the edges of discovery?

  Marc came to her rescue. After days of grunt work, the scientist in him yearned for this last chance as much as she did. "We can do it in two days. We'll work here tomorrow morning, drive to the site and set up the pulleys by nightfall. Next day we'll explore the vent and come back. That gives us a full day to finish up here before liftoff." He looked at Piotr and Raoul. "We feel we have to do this."

  Technically, the two scientists could amend mission plans if they felt it was warranted. Clearly they would do so this time.

  Raoul looked pensive. "I want to go over the thruster assembly again. Something might need adjustment after the burn we just did." He hurried on, "But I can do it alone."

  In a flash Ann understood that Raoul wished to take responsibility for the repairs, needed to have time alone with his handiwork. He would be just as happy not to have two itchy scientists underfoot. Then he could take as much time as he liked, obsess over every detail.

  There was a long moment. They skirted the edge of a rift. Finally Piotr nodded agreement. He had followed Ann's arguments carefully, hoping to be convinced. Now he snapped back into mission commander mode. "Da. All right. Two days only."

  Ann's heart soared. She flashed him a brilliant smile, leaned over and, ignoring mission discipline, gave him a big kiss. Spendin
g one final night in a hellishly cold rover would be the price, but well worth it. She was going to explore the vent at last!

  PART 3

  She woke to the bitter tang of black Colombian perking in the pot, the scent mingling with a buttery aroma of pancakes, the sizzle of bacon in its lake of fat, all lacing in their steamy collaboration to make a perfect moist morning And then she snapped awake, really awake-on the hard rover bunk, hugging herself in her thermoelectric blanket. Once all her waking dreams had been about sex; now they were about food. She wasn't getting enough of either, especially not since Piotr's ankle.

  The break would heal by the time they were on the long glide Earthward; their rations would not improve until they were back eating steak. She pushed the thought of meat out of her mind and sat up. First feelers of ruddy dawn laced a wisp of carbon dioxide cirrus high up; good. Today she got to burrow, at last.

  "Hey, Marc! I'll start the coffee."

  No dallying over breakfast, though the hard cold that came through the rover walls made her shiver. A ruddy sunup was just breaking, giving them one final day of exploration. She peered out the viewport as she munched. They would run on in-suit rations today, no returning to the Spartan comforts of the rover.

  They had set up the cable rig at the edge of the vent before sundown. By early light it still looked secure, anchored to three boulders. Marc didn't trust the soil here to hold so they had arranged cross-struts of their monofilament-based cabling to take their weight as they went down the steep incline. Metal cable was much too heavy to fly to Mars, and not necessary under the lighter gravity.

  The first part was easy, just backing over. The rock was smooth and of course dry. Even if vapor had spouted last night, it would never condense for long. The Martian atmosphere was an infinite sponge.

  The vent snaked around and steepened as the pale light of late dawn from above lost out to the gloom. The rock walls were smooth and still about 10 meters wide. They reached a wide platform and the passage broadened farther. Every 10 meters down they checked to be sure the cable was not getting fouled. They were both clipped to it and had to time their movements to keep from getting snarls.

  They edged along the ledge cautiously, headlamps stabbing into the darkness. She was trying to peer ahead but her eyes were cloudy for some reason. She checked her face-plate but there was no condensate on it; the little suit circulators took care of that, even in the cold of full Martian night. Still, the glow from Marc's suit dimmed.

  "Marc, having trouble seeing you. Your lamp die?"

  "Thought I was getting fogged. Here-" He clambered over on the steep slope of the ledge and shone his handbeam into her face. "No wonder. There're drops of something all over your face-plate and helmet. Looks like water drops!"

  "Water ... ?"

  "We're in a fog!" He was shouting.

  She saw it then, a slow, rising mist in the darkness. "Of course! It could be a fog desert in here."

  "A what?"

  "Ever been out in a serious fog? There's not much water falling, but you get soaked anyway. There are deserts where it doesn't rain for years, like the Namib and the coast of Baia California. Plants and animals living there have to trap the fog to get water." She thought quickly, trying to use what she knew to think about this place. In fact, frogs and toads in any desert exploited a temperature differential to get water out of the air even without a fog. When they came up out of their burrows at night they were cooler than the surrounding air. Water in the air condensed on their skin, which was especially thin and permeable.

  Ann peered at the thin mist. "Are you getting a readout of the temperature?

  What's it been doing since we started down?"

  He fumbled at his waist pack for the thermal probe, switched it to readout mode. "Minus 14, not bad." He thumbed for the memory and nodded. "It's been climbing some, jumped a few minutes ago. Hm. It's warmer since the fog moved in."

  They reached the end of the ledge, which fell away into impenetrable black. "Come on, follow the evidence," she said, playing out cable through her clasps. Here the low gravity was a big help. She could support her weight easily with one hand on the cable grabber, while she guided down the rock wall with the other.

  "Evidence of what?" Marc called, grunting as he started down after her.

  "A better neighborhood than we've been living in."

  "Sure is wetter. Look at the walls."

  In her headlamp the brown-red rock had a sheen. "Enough to stick!"

  "I can see fingers of it going by me. Who woulda thought?"

  She let herself down slowly, watching the rock walls, and that was why she saw the subtle turn in color. The rock was browner here and when she reached out to touch it there was something more, a thin coat. That! There's a mat here."

  "Algae?"

  "Could be." She let herself down farther so he could reach that level. The brown scum got thicker before her eyes. "I bet it comes from below."

  She contained her excitement as she got a good shot of the scum with the recorder and then took a sample in her collector rack. Warmer fog containing inorganic nutrients would settle as drops on these cooler mats. Just like the toads emerging from their burrows in the desert? Analogies were useful, but data ruled, she reminded herself. Stick to observing. Every moment here will get rehashed a million-fold by every biologist on Earth ... and the one on Mars, too.

  Marc hung above her, turning in a slow gyre to survey the whole vent. "Can't make out the other side real well, but it looks brown, too."

  "The vent narrows below." She reeled herself down.

  "How do they survive here? What's the food source?"

  "The slow-motion upwelling, like the undersea hydrothermal vents on Earth?"

  Marc followed her down. "Those black smokers?"

  She had never done undersea work but was of course aware of the sulfur-based life at the hydrothermal vents. Once it was believed that all life on Earth depended on sunlight, trapped by chlorophyll in green plants and passed up the food chain to animals. Then came the discovery of sunlight-independent ecosystems on the ocean floor, a fundamental change in a biological paradigm. The exotic and unexpected vent communities were based on microbes that harnessed energy from sulfur compounds in the warm volcanic upwelling. Meter-long tube worms and ghostly crabs in turn harvested the bacteria. The vent communities on earth were not large, a matter of meters wide before the inexorable cold and dark of the ocean bottom made life impossible. She wondered how far away the source was here.

  In the next 50 meters the scum thickened but did not seem to change. The brown filmy growth glistened beneath her headlamp as she studied it, poked it, wondered at it.

  "Marsmat," she christened it. "Like the algal mats on Earth, a couple of billion years ago." Marc said wryly, puffing, "We spent months looking for fossil evidence, up there in the dead sea beds. The real thing was hiding from us down here."

  The walls got closer and the mist cloaked them now in a lazy cloud. "You were right," Marc said as they rested on a meter-wide shelf. They were halfway through their oxygen cycle time. "Mars made it to the pond scum stage."

  "Not electrifying for anybody but a biologist, but something better than individual soil microbes. It implies a community of organisms, several different kinds of microbes aggregated in slime-a biofilm." She peered down. "You said the heat gradient is milder here than on Earth, right?"

  "Sure. Colder planet anyway, and lesser pressure gradient because of the lower gravity. On Earth, 1 klick deep in a mine it is already 56 degrees C. So?"

  "So microbes could probably survive farther down than the couple of klicks they manage on Earth. They're stopped by high heat."

  "Maybe."

  "Let's go see."

  "Now? You want to go down there now?"

  "When else?"

  "We're at oxy turnaround point."

  "There's lots in the rover."

  "How far down do you want to go?"

  "As far as possible. There's no tomorrow.
Look, we're here now, let's just do it."

  He looked up at his readouts. "Let's start back while we're deciding."

  "You go get the tanks. I'll stay here."

  "Split up?"

  "Just for a while."

  "Mission protocol-"

  "Screw protocol. This is important."

  "So's getting back alive."

  " I'm not going to die here. Co down maybe 50 meters, tops. Got to take samples from different spots."

  "Piotr said-"

  "Just go get the tanks."

  He looked unhappy. "You're not going far, are you?"

  "No."

  "OK then. I'll lower them down to the first ledge if you'll come back that far to pick them up. Then I'll come down, too."

  "OK, sounds fine. Let's move."

  He turned around and started hauling himself up the steep wall. "Thirty minutes, then, at the first ledge."

  "Yeah, fine. Oh, and bring some batteries, too. My handbeam's getting feeble."

  "Ami "See you in 30 minutes," she said brightly, already moving away. Marc kept going. The slope below was easy and she inched down along a narrow shelf. Playing out the cable took her attention. Methodical, careful, that's the ticket. Especially if you're risking your neck deep in a gloomy hole on an alien world.

  She felt a curious lightness of spirit-she was free. Free on Mars. For the last time. Free to explore what was undoubtedly the greatest puzzle of her scientific life. She couldn't be cautious now. Her brother Bill flashed into her mind. He took life at a furious pace, cramming each day full, exuding boundless energy. They went on exploring trips together as children, later as nascent biologists. He was unstoppable: up and out early, roaming well after dark. There was never enough time in the day for everything he wanted to see. "Slow down, there's always tomorrow," people would tell him.

  But his internal clock had served him well, in a way. He was cut down at age 22 when his motorcycle slid into a truck one rainy night when sensible people were home, warm and dry. Looking around the church at his funeral, Ann felt he'd lived more than most of the middle-aged mourners. Bill would've approved of her right now, she was sure.