The Year's Best Science Fiction: Fifteenth Annual Collection

by Gardner Dozois

  A map was laid over the cross section, every feature familiar. Save one.

  "Madam," said a sturdy voice. Miocene's voice. "It's an anomaly, granted. But doesn't the feature seem rather ... unlikely ... ?"

  "Which is why I thought it was nothing. And my trusted Al-part of my own neural net-agreed with me. This region is a change in composition. Nothing more." She paused for a long moment, watching her captains. Then with a gracious oversized smile, she admitted, "The possibility of a hollow core has to seem ludicrous."

  Submasters and captains nodded with a ragged hopefulness.

  Knowing they weren't ordered here because of an anomaly, Washen stepped closer. How large was it? Estimates were easy to make, but the simple math created some staggering numbers.

  "Ludicrous," the Master repeated. "But then I thought back to when we were babies, barely a few thousand years old. Who would have guessed that a Jupiter class world could become a starship like ours?"

  Just the same, thought Washen: Certain proposals will always be insane.

  "But madam," said Miocene. "A chamber of those proportions would make us less massive. Assuming we know the densities of the intervening iron, of course ... "And you're assuming, of course, that the core is empty." The Master grinned at her favorite officer, then at all of them. For several minutes, her expression was serene, wringing pleasure out of their confusion and ignorance.

  Then she reminded everyone, "This began as someone else's vessel. We shouldn't forget: We don't understand why our home was built. For all we know, it was a cargo ship. A cargo ship, and here is its hold."

  The captains shuddered at the idea. "Imagine that something is inside this chamber. Like any cargo, it would have to be restrained. A series of strong buttressing fields might keep it from rattling around every time we adjusted our course. And naturally, if the buttressing fields were rigid enough, then they would mask whatever is down there-"

  "Madam," shouted someone, "please, what's down there ... Shouted Diu.

  "A spherical object. It's the size of Mars, but considerably more massive." The Master grinned for a moment, then told the projection, "Please. Show them what I found."

  The image changed again. Nestled inside the great ship was a world, black as iron and slightly smaller than the chamber surrounding it. The simple possibility of such an enormous, unexpected discovery didn't strike Washen as one revelation, but as many, coming in waves, making her gasp and shake her head as she looked at her colleagues' faces, barely seeing any of them.

  "This world has an atmosphere," said the laughing voice, "with enough oxygen to be breathed, enough water for lakes and rivers, and all of the symptoms usually associated with a vigorous biosphere-"

  "How do we know that?" Washen called out. Then, in a mild panic, "No disrespect intended, madam!"

  "I haven't gone there myself, if that's what you're asking." She giggled like a child, telling them, "But after fifty years of secret work, using self-replicating drones to rebuild one of the old tunnels ... after all that, I'm able to stand here and assure you that not only does this world exist, but that each of you are going to see it for yourselves ..."

  Washen glanced at Diu, wondering if her face wore that same wide smile.

  "I have named the world, by the way. We'll call it Marrow." The Master winked and said, "For where blood is born, of course. And it's reserved for you ... my most talented, trustworthy friends ... !"

  Wonders had been accomplished in a few decades. Mole-like drones had gnawed their way through beds of nickel and iron, repairing one of the ancient tunnels; fleets of tube-cars had plunged to where the tunnel opened into the mysterious chamber, assembling a huge stockpile of supplies directly above Marrow; then a brigade of construction drones threw together the captains' base camp-a sterile little city of dormitories, machine shops, and first-rate laboratories tucked within a transparent, airtight blister.

  Washen was among the last to arrive. At the Master's insistence, she led a cleaning detail that stayed behind, erasing every trace of the captains' presence from the leech habitat. It was a security precaution, and it required exacting work. And some of her people considered it an insult. "We aren't janitors," they grumbled. To which Washen replied, "You're right. Professionals would have finished last week."

  Diu belonged to her detail, and unlike some, the novice captain worked hard to endear himself. He was probably calculating that she would emerge from this mission as a Submaster and his benefactor. But there was nothing wrong in calculations, Washen believed-as long as the work was done, successes piled high and honors for everyone.

  Only tiny, two passenger tube-cars could make the long fall to the base camp. Washen decided that Diu would provide comfortable company. He rewarded her with his life story, including how he came into the captains' ranks. "After a few thousand years of being a wealthy passenger, I realized that I was bored." He said it with a tone of confession, and amusement. "But you captains never look bored. Pissed, yes. And harried, usually. But that's what attracted me to you. If only because people expect it, captains can't help seem relentlessly, importantly busy."

  Washen had to admit, it was a unique journey into the ship's elite.

  At journey's end, their car pulled into the first empty berth. On foot, Diu and Washen conquered the last kilometer, stepping abruptly out onto the viewing platform, and not quite standing together, peering over the edge.

  A tinted airtight blister lay between them and several hundred kilometers of airless, animated space. Force fields swirled through that vacuum, creating an array of stubborn, stable buttresses. The buttresses were visible as a brilliant blue-white light that flowed from everywhere, filling the chamber. The light never seemed to weaken. Even with the blister's protection, the glare was intense. Relentless. Eyes had to adapt-a physiological change that would take several ship-days-and even still, no one grew accustomed to the endless day.

  Even inside her bedroom, windows blackened and the covers thrown over her head, a captain could feel the radiance piercing her flesh just so it could tickle her bones.

  The chamber wall was blanketed with a thick mass of gray-white hyperfiber, and the wall was their ceiling, falling away on all sides until it vanished behind Marrow.

  "Marrow," Washen whispered, spellbound.

  On just the sliver of the world beneath them, the captain saw a dozen active volcanoes, plus a wide lake of bubbling iron. In cooler basins, hot-water streams ran into colorful, mineral-stained lakes. Above them, water clouds were gathering into enormous thunderheads. When the land wasn't exploding, it was a rugged shadowless black, and the blackness wasn't just because of the iron-choked soils. Vigorous, soot-colored vegetation basked in the endless day. And they were a blessing. From what the captains could see, the forests were acting as powerful filters, scrubbing the atmosphere until it was clean, at least to where humans, if conditioned properly, should be able to breathe, perhaps even comfortably.

  "I want to get down there," Washen confessed.

  "It's going to take time," Diu warned, pointing over her shoulder.

  Above the blister, dormitories and machine shops were dangling from the hyperfiber, their roofs serving as foundations. Past them, at the blister's edge, the captains were assembling a silvery-white cylinder. It would eventually form a bridge to Marrow. There was no other way down. The buttress fields killed transports, and for many reasons, unprotected minds eroded in an instant, and died. To beat the challenge, their best engineer, Aasleen, had designed a shaft with its interior shielded with quasiceramics and superfluids. Theories claimed that the danger ended with Marrow's atmosphere, but just to be safe, several hundred immortal pigs and baboons were in cages, waiting to put those guesses to the test.

  Washen was thinking about the baboons, and timetables.

  A familiar voice broke her reverie.

  "What are your impressions, darlings?"

  Miocene stood behind them. In uniform, she was even more imposing, and more cold. Yet Washen summoned
her best smile, greeting the mission leader, then adding, "I'm surprised. I didn't know it would be this beautiful."

  "Is it?" The knife-edged face offered a smile. "Is there any beauty here, Diu?"

  "A spartan kind of beauty," Diu replied.

  "I wouldn't know. I don't have any feel for aesthetics." The Submaster smiled off into the distance. "Tell me. If this world proves harmless and beautiful, what do you think our passengers will pay for the chance to come here?"

  "If it's a little dangerous," Washen ventured, "they would pay more."

  Miocene's smile came closer, growing harder. "And if it's deadly, maybe we'll have to collapse the tunnel again. With us safely above, of course."

  "Of course," the captains echoed.

  Diu was grinning, with his face, and if possible, with his entire body.

  Mirrors and antennae clung to hyperfiber, gazing at Marrow. He gestured at them, asking, "Have we seen any signs of intelligence, madam? Or artifacts of any sort?"

  "No," said Miocene, "and no."

  It would be a strange place for sentience to evolve, thought Washen. And if the builders had left ruins behind, they would have been destroyed long ago. The crust beneath them wasn't even a thousand years old. Marrow was an enormous forge, constantly reworking its face as well as the bones beneath.

  "I can't help it," Diu confessed. "I keep dreaming that the builders are down there, waiting for us."

  "A delirious dream," Miocene warned him.

  But Washen felt the same way. She could almost see the builders slathering the hyperfiber, then building Marrow. This was a huge place, and they couldn't see more than a sliver of it from their tiny vantage point. Who knew what they would eventually find?

  Diu couldn't stop talking. "This is fantastic," he said. "And an honor. I'm just pleased that the Master would include me."

  The Submaster nodded, conspicuously saying nothing.

  "Now that I'm here," Diu blubbered, "I can almost see the purpose of this place."

  With a level glance, Washen tried to tell her companion, Shut up.

  But Miocene had already tilted her bead, eyeing their eleventh-grade colleague. "I'd love to bear your theories, darling."

  Diu lifted his dark eyebrows.

  An instant later, with bleak amusement, he remarked, "I think not." Then he looked at his own hands, saying, "Once spoken, madam, the useful belongs to at least one other soul."

  MISSION YEAR 1.03:

  Planetfall was exactly as the captains had planned-a routine day from the final five kilometers of bridge building to Miocene's first steps on the surface. And with success came cheers and singing, followed by ample late suppers served with bottomless glasses of well-chilled champagne, and congratulations from the distant Master. Except for Washen, the day was just a little disappointing.

  Watching from base camp, studying data harvests and live images, she saw exactly what she expected to see. Captains were administrators, not explorers; the historic moments were relentlessly organized. The landscape had been mapped until every bush and bug had a name. Not even tiny surprises could ambush the first teams. It was thorough and stifling, but naturally Washen didn't mention her disappointment, or even put a name to her emotions. Habit is habit, and she had been an exemplary captain for thousands of years. Besides, what sort of person would she be if she was offended that there were no injuries, or mistakes, or troubles of any kind?

  And yet.

  Two ship-days later, when her six-member team was ready to embark, Washen had to make herself sound like a captain. With a forced sincerity, she told the others, "We'll take our walk on the iron, and we'll exceed every objective. On schedule, if not before."

  It was a swift, strange trip to Marrow.

  Diu asked to ride with Washen, just as he'd requested to be part of her team. Their shielded tube-car retreated back up the access tunnel, then flung itself at Marrow, streaking through the buttress fields to minimize the exposure, a trillion electric fingers delicately playing with their sanity.

  Then their car reached the upper atmosphere and braked, the terrific gees bruising flesh and shattering minor bones.

  Artificial genes began weaving protein analogs, knitting their injuries.

  The bridge was rooted into a hillside of cold iron and black jungle. The rest of the team and their supplies followed. Despite an overcast sky, the air was brilliant and furnace-hot, every breath tasting of metal and nervous sweat. As team leader, Washen gave orders that everyone knew by heart. Cars were linked, then reconfigured. The new vehicle was loaded, and tested, and the captains were tested by their autodocs: Newly implanted genes were helping their bodies adapt to the heat and metal-rich environment. Then Miocene, sitting in a nearby encampment, contacted them and gave her blessing, and Washen lifted off, steering towards the purely arbitrary north-northwest.

  The countryside was broken and twisted, split by fault lines and raw mountains and volcanic vents. The vents had been quiet for a century or a decade, or in some cases, days. Yet the surrounding land was alive, adorned with jungle, pseudotrees reminiscent of mushrooms, all enormous, all pressed against one another, their lacquered black faces feeding on the dazzling blue-white light.

  Marrow seemed as durable as the captains flying above it.

  Growth rates were phenomenal, and for more reasons than photosynthesis. Early findings showed that the jungle also fed through its roots, chisel-like tips reaching down to where thermophilic bacteria thrived, Marrow's own heat supplying easy calories.

  Were the aquatic ecosystems as productive?

  It was Washen's question, and she'd selected a small, metal-choked lake for study. They arrived on schedule, and after circling the lake twice, as prescribed, she landed on a slab of bare iron. Then for the rest of the day they set up their lab and quarters, and specimen traps, and as a precaution, installed a defense perimeter-three paranoid Als who did nothing but think the worst of every bug and spore that happened past.

  Night was mandatory. Miocene insisted that each captain sleep at least four hours, and invest another hour in food and toiletries.

  Washen's team went to bed on time, then lay awake until it was time to rise.

  At breakfast, they sat in a circle and gazed at the sky. The chamber's wall was smooth and ageless, and infinitely bland. Base camp was a dark blemish visible only because the air was exceptionally clear. The bridge had vanished with the distance. If Washen was very careful, she could almost believe that they were the only people on this world. If she was lucky, she forgot for a minute or two that telescopes were watching her sitting on her aerogel chair, eating her scheduled rations.

  Diu sat nearby, and when she glanced at him, he smiled wistfully, as if he could read her thoughts.

  "I know what we need," Washen announced.

  Diu said, "What do we need?"

  "A ceremony. Some ritual before we can start." She rose and walked to one of the specimen traps, returning with one of their first catches. On Marrow, pseudoinsects filled almost every animal niche. Six-winged dragonflies were blue as gemstones and longer than a forearm. With the other captains watching, Washen stripped the dragonfly of its wings and tail, then cased the rest into their autokitchen. The broiling took a few seconds. With a dull thud, the carcass exploded inside the oven. Then she grabbed a lump of the blackish meat, and with a grimace, made herself bite and chew. "We aren't supposed to," Diu warned, laughing gently.

  Washen forced herself to swallow, then she told everyone, "And you won't want to do it again. Believe me."

  There were no native viruses to catch, or toxins that their reinforced genetics couldn't handle. Miocene was simply being a cautious mother when she told them, "Except in emergencies, eat only the safe rations."

  Washen passed out the ceremonial meat.

  Last to take his share was Diu, and his first bite was tly. But he didn't grimace, and with an odd little laugh, he told Washen, "It's not bad. If my tongue quit burning, I could almost think about enjoying it."
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br />   MISSION YEAR 1.22:

  After weeks of relentless work, certain possibilities began to look like fact.

  Marrow had been carved straight from the Jupiter's heart. Its composition and their own common sense told the captains as much. The builders had first wrenched the uraniums and thoriums from the overhead iron, injecting them deep into the core. Then with the buttressing fields, the molten sphere was compressed, and the exposed chamber walls were slathered in hyperfiber. And billions of years later, without help from the vanished builders, the machinery was still purring along quite nicely.

  But why bother creating such a marvel?

  Marrow could be a dumping ground for radionuclides. Or it could have worked as an enormous fission reactor, some captains suggested. Except there were easier ways to create power, others pointed out, their voices not so gently dismissive.

  But what if the world was designed to store power?

  It was Aasleen's suggestion: By tweaking the buttresses, the builders could have forced Marrow to rotate. With patience-a resource they must have had in abundance-they could have given it a tremendous velocity. Spinning inside a vacuum, held intact by the buttresses, the iron ball would have stored phenomenal amounts of energy-enough to maintain the on board systems for billions of years, perhaps.

  Washen first heard the flywheel hypothesis at the weekly briefing.

  Each of the team leaders was sitting at the illusion of a conference table, in aerogel chairs, sweating rivers in Marrow's heat. The surrounding room was sculpted from light, and sitting at the head of the table was the Master's projection, alert but unusually quiet. She expected crisp reports and upbeat attitudes. Grand theories were a surprise. Finally, after a contemplative pause, she smiled, telling the captain, "That's an intriguing possibility. Thank you, Aasleen." Then to the others, "Considerations? Any?"