The Mammoth Book of Best New SF 25

by Gardner Dozois

  The figures on the platforms and terraces broke apart, bowed to each other, lost all pattern and rhythm and became random again. Moving Day Down was over for another half-year. Tash flicked on the Common Channel. Tash liked to be apart, different, a girl of words and wit, but she also loved to be immersed in West Diggory’s never-ending babble of chat and gossip and jokes and family news. Together, the Excavating Cities had a population of less than two thousand humans. Small, complex societies, isolated from the rest of the planet, gush words like springs, like torrents and floods. The river of words, the only river that Mars knew. Tash’s psuit circuitry was smart enough to adjust the voices so that they spoke at the volume and distance they would have in atmosphere. Undifferentiated, the flood of West Diggory voices would have overwhelmed her so the wall of voices did not overwhelm her. She turned her head this way, that way. Eavesdropping. There was Leyta Soshinwe-Opunyo, Queen-beeing again. Tash had seen pictures of bees like she had seen birds. On Arrival Day, when the Excavating Cities finally reached the bottom of the Big Dig, there would be birds, and bees, and even spiders. There was Great-Out-Aunt Yoto, seeming enthusiastic but always seasoned with a pinch of criticism – oh, and another thing: people weren’t performing the dance moves right, the Engineers had mistuned the tokamaks and her titanium hip was aching, was it her or did more bits fall off West Diggory every time? They would never have allowed that in Southdelving, her family home. A sudden two-tone siren cut across the four hundred voices of West Diggory. Emergency teams slapped their psuits to warning yellow and rushed to their positions, everyone hurried to the muster points, then relaxed as the medics discovered the nature of the Emergency. The Common Channel flooded with laughter. Haramwe Odonye, during a particularly energetic caper in the West Diggory Down, had slipped and sprained his ankle.

  Big Dig Figs:

  Population: one thousand eight hundred and thirty three, divided between the four Excavating Cities of (clockwise) Southdelving, West Diggory, North Cutter and A.R.E.A (Ares Re-engineering of Environment and Atmosphere). Total Martian population: five thousand two hundred and seventeen.

  Elevation: at the digging head as of Martian Year 112, Janulum 1: minus twenty three kilometres below Martian Mean Gravity Surface (no sea level). Same date, highest point of Mt. Impossible: 15 kilometres above MGS.

  Diameter of the Big Dig at Martian MGS: Five hundred and sixteen kilometres.

  Circumference of the Big Dig at Martian MGS: One thousand six hundred and twenty two kilometres.

  Angle of Big Dig Excavation Surface: 5:754 degrees. That’s pretty gentle. The scoopline can’t handle more than an eight-degree slope. To the casual human eye – one that hasn’t grown up inside the gentle dish of the Big Dig, that would look almost flat. But it’s not flat. That’s why it’s the key figure: those 5:75 degrees are going to make Mars habitable.

  Date of commencement of the Big Dig: AlterMarch 23rd, Martian Year 70. Two thirty in the afternoon, on schedule, the scooplines excavated and the bucket teeth took their first bites of Isidis Planitia.

  Volume of the Big Dig: as of above date: one million, eight hundred and thirteen thousand cubic kilometres. All piled up neatly into Mt. Impossible, the ring-shaped mountain that surrounds the Big Dig like the wall of an old impact crater. Not entirely surrounds. Mt. Impossible has been constructed with four huge valleys: Windrush, Zephyr, Cyroco and Storm of the Black Plums: howling wind-haunted, storm-scoured canyons: that same wind singing over the tombs of the Diggers who have died in the course of the great excavation, unfailingly stirring the flags and streamers of the mobile cities far below.

  Total mass of Martian surface excavated in the Big Dig to date: 7.1 × 1015 tons.

  Big Dig Figs and Facts. The numbers that shape Tash’s world.

  Tash was in the Orangery when the call came down through the rows of breadfruit trees. Like the Moving Day dance, the name was generally considered another joke that had run away and taken up residence in the ventilators and crawlspaces and power conduits of the Excavating City, as this baroque glass dome had never grown oranges. The rows of breadfruit and plantains and bananas and other high-carbo staples gave camouflage and opportunity for West Diggory’s young people to meet and talk and scheme and flirt.

  “Milaba wants to see, Tash, pass it on.”

  “Sweto, tell Chunye that Milaba wants to see Tash.”

  “Qori, have you seen Tash?”

  “I think she was down in the plantains, but she might have moved on to the breadfruit.”

  “Well tell her Milaba wants to see her.”

  By leaps and misunderstandings, by staggers and misapprehensions, by devious spirals of who liked who and who was talking to who and who wasn’t and who was hooking with who and who had finished with who, the message spiralled in along the web of leaf-mould-smelling plants to Tash, spraying the breadfruit. A simple call, a message would have reached her directly but where there are only a hundred of you, true social networking is mouth to mouth.

  In-Aunt Milaba. She was a legend, a statue of woman, gracious and noble, adored far beyond West Diggory. Her dark skin was lustrous as night, her soul as star-filled. To be in her presence was to be blessed in ways you would not immediately understand but, more thrilling to Tash, was that In-Aunt Milaba was the chief service engineer for the North West sector scooplines. The summons to her office, a little glass and aluminium bubble like a bunion on one of West Diggory’s steel feet, could mean only one thing. Out. Out and up.

  “So Haramwe sprained his ankle.”

  Every part of In-Aunt Milaba’s tiny office, from the hand-carved olivine desk to the carafe of water that stood on it, shook to the rattle of the buckets hurtling up the scoopline. Milaba raised an eyebrow. Tash realized a response was due.

  “Are his injuries debilitating?”

  “Debilitating.” Milaba gave a flicker of a smile. “You could say that. He’ll be out for a week or so. He came down heavily, silly boy. Showing off. When is your birthday?” Tash’s heart leapt.

  She knew. Everyone knew everything, all the time. The game was pretending not to know.

  “Octobril fifth.”

  “Three months.” Milaba appeared to consider for a moment. “Peyko Ruebens-Opollo says for all your fancy talk you’ve a good head and better sense and do what you’re told. That’s good because I don’t need attitude problems or last-minute-good-ideas when I’m out on the line.”

  For once the words failed Tash. They hissed from her like air from a ruptured atmosphere cell. She waved her hands in speechless delight.

  “I’m taking a digger up Line 12 to Windrush Valley. The feed tokamaks have been fluctuating nastily. Probably a soft fail in a command chip set; they get a lot of radiation up there. Now I need someone with me to hold things and make tea and generally make intelligent conversation. Are you interested?”

  Still the words would not come. The rule was that you did not leave the Excavating Cities until you were eight, when you were technically adult. Rules broke and bent with the frequency of scoopline breakdowns but three months was a significant proportion of the long Martian year. Out. Out, and up. Up the line, into the windy valley. In a diggler, with In-Aunt Milaba.

  “Yes, oh yes, I’d love to,” Tash finally squeaked. Now Milaba unleashed the full radiance of her smile and it was like sunrise, it was solstice lights, it was the warmth of the glow-lamps in the Orangery. I say you are an adult citizen of West Diggory, Tash Gelem-Opunyo, the smile said, and if I say it, all say it.

  “Be at the Outlock 12 at fourteen o’clock,” Milaba said. “You do know how to make tea, don’t you?”

  * * *

  Still not got it? It’s easy, easy easy easy. Easy as a heezy, which is a Digger saying. A heezy is the lever on a scoopline bucket that, when struck by the dohbrin (which is a different type of lever found at the load-off end of the scoopline) tips the contents of the bucket down Mt. Incredible. Heezy peasy easy. It’s all because air has weight. Air’s not nothing. It’s gas – in Mar
s’ case, carbon dioxide nitrogen argon oxygen and the leaked breathings from the hundred-and-something years that humans have scratched and scrabbled clawholds on its red earth. It has mass. It has weight. And it flows, the same way that water flows, to the lowest point. Wind is air flowing. People say, no one knows why the wind blows. That’s stupid nonsense. Wind blows from high to low, high pressure to low pressure, high altitude to low altitude; down the slopes of mountains, through canyons and valleys. The air pressure at the bottom of the great and primeval rift of Valles Marineris is ten times that in the long-cold volcanic calderas atop Olympus Mons. Titanic gales and fog blow through that valley. The fog is because the atmospheric pressure at the bottom of the valley is enough – just enough – to allow water to exist as vapour. But that’s still not enough to support big life. That’s like higher than earth’s highest mountain. That’s fingertip-lip-exploding, eyeball-squelching, cheek-bursting pressure. Bug life yes, big life no. That’s not enough to make Mars a green paradise, a home for humanity, a fertile pool of life beyond little blue Earth. What you need is deep. Thirty kilometres deep. Deeper than any place on Earth is deep. Deeper than even Olympus Mons, mightiest mountain on all the worlds, is high. And because air has weight, because atmosphere flows and the wind blows, gas will fill up the hole. That’s the wind that rattles the banners and turns the rotors of West Diggory. As the gas flows the pressure grows until the day comes when the atmospheric pressure at the bottom of the hole is enough for you to walk around without a psuit, in just your skin if you have the urge and your skin is pretty enough. Earth atmospheric pressure. Pressure, that’s always been the problem with making Mars habitable. Get all the gas into one place. When you’ve got enough of it, turning it into something you can breathe is the easy bit. That’s just bugs and plants and life.

  Thirty kilometres deep. The scooplines are at minus twenty-six kilometres. That’s another five M-years before they hit atmospheric baseline. Then they’ll level out the floor of the crater, take away some of the sides, expand the flat area, though it will all seem so flat, the atmospheric gradient so subtle, that you will seem to be walking out into breathlessness and light-headedness rather than ascending into it. Fifty years after her In-Grandfather Tayhum made the first incision, the Big Dig will be dug. Tash will be seventeen and a half when the wind rushing down the sides of the Big Dig finally fails and the rotors stop and the banners fall and the Excavating Cities finally come to a rest.

  Twenty-six kilometres up slope, In-Aunt Milaba gave the sign for Tash to throw the levers to disengage the diggler from the scoopline. Thus far the big world of outside had been a thumping disappointment to Tash. She had yet to be outside, properly outside, two-figures-in-a-Mars-scape outside, shiver-in-your-psuit outside. She had transited from plastic bubble by plastic tube to plastic bubble connected by its grip on the scoopline to home.

  This was what Tash Gelem-Opunyo saw from the transparent bubble of the diggler. Sand sand sand sand sand, a rock there, sand sand sand rock rock, oh, some pebbles! Sand grit sand more grit something between pebble and grit, something between grit and sand, a bit of old abandoned machinery, wow wow wow! Dust drifted up around it. Sand. Sand. Sand. West Diggory was still visible, down the dwindling thread of the scoopline, now truly the size of a spider. The enormous, horizonless perspectives robbed Tash of anything by which she could judge movement. The sand, the buckets, the unchanging gentle gradient that went up halfway to space. Only by squinting down through the floor glass at the blurred, grainy surface did she get any sense of movement.

  Twenty-six vertical kilometres equalled two hundred sixty surface kilometres equalled five and a half hours in a plastic bubble with a relative you’ve grown up in enforced proximity to but until now never really known or talked to. Everyone loves In-Aunt Milaba the Magnificent, that’s the legend, but five hours, Aunt and Niece, Tash began to wonder if this was another wind-whisper legend blown around the corners and crannies of West Diggory. She was beautiful, a feast for the eye and soul, all those things an eight-year-old girl hopes for herself (and did Tash not share the DNA – given that the Excavating cities genepool was shallow as a spit, hence all the careful arrangements of In-relatives and Out-relatives and who would be sent to one of the other Excavating Cities and who would stay) all those things a girl of almost-eight wants for herself but try as she might, and did, Tash could not engage her. Fancy funny words of the type Tash treasured. Poems. Puns. Riddles. Guessing games. Break-the-code-games. Allusions and circumspect questions. Direct questions. To them all In-Aunt Milaba shook her head and smiled and bent over the controls and the monitors and checked her kit and said not a word. So tea, lots of tea, and muttering little rhymes to the rhythm of the huge balloon wheels as the scoopline hauled Diggler Six up the side of the biggest excavation in the solar system.

  But now they were released from the scoopline and Milaba was standing at the steering column, driving the diggler under its own power. It was still sand sand sand and occasional rock, but Tash knew a gnaw of excitement. She was free, disconnected from the umbilicals of life for the first time. She was out in the wild world. The scoopline dwindled to a thread, to invisibility behind her, ahead she saw a notch on the edge of vision. Windrush Valley. All the wind-blown words stopped. A flaw in the horizon. A place beyond the Big Dig. Beyond that declivity was the whole curved world. In the silence In-Aunt Milaba turned from the control column.

  “I think you could have a go now.”

  So this was what she had been waiting for, Tash to run out of words, and finally listen.

  The diggler was ridiculously simple to drive. Plant your feet firmly at the drive column. Push forward to feed power to the traction motors in the wheel hubs. Pull back to brake. Yaw to steer. There was even a little holder on the side of the drive column for your tea. Tash giggled with nervous glee as she gingerly pushed forward the stick and the bubble of pressure glass slung between the giant orange tyres stuttered forward. Within thirty seconds she had it. Thirty seconds later she was pushing it, sneaking the speed bar up, looking for places where she could make the diggler skip over rocks.

  “I’d go easy on that throttle,” Milaba said. “The battery life is eight hours; That’s why we ride the scoopline up and down again. You don’t want to get stuck up here with night coming down, no traction and no heat.”

  Tash eased the stick back but not before the diggler hit the small boulder at which she had discreetly aimed and bounced all four wheels in the air. Milaba smiled that morning-sun smile. Then shoulder by shoulder they stood at the controls and rode up into the orange valley. The land rose up on either side, higher as they drove deeper, kilometres high. They felt like oppression to Tash, shouldering close and ominous, their heights breathless and haunted with dark things that lived in the sky. At the same time she felt hideously small and exposed in the fragile glass ornament of the diggler. The wind was rising, she could feel the diggler shake on its suspension, hear the shriek and moan through the cables. The controls fought her but she pushed the little bubble deeper and deeper into Windrush Valley. When her forearms ached and the sinews on her neck stood out from fighting the atmosphere of Mars pouring through this two-kilometre wide notch in Mt. Incredible, Milaba leaned over and tapped a pre-programmed course into the computer.

  “Suit up,” she said. “We’ll be there in ten minutes.”

  The tokamak station was a wind-scoured blister of construction plastic hunkering between a boulder field and a stretch of polished olivine. It was only when the diggler slowed to a stop and fired sand anchors that Tash realized that it was near and smaller than she had thought. It was not a distant vast city, the power plant was only slightly higher than the diggler’s mammoth wheels. The wind rotor, spinning like it would suddenly leap from its pylon and spin madly away through the upper air, was no bigger than her outstretched hands.

  “Mask sealed?”

  Tash ran her fingers around the join with her psuit hood and gave In-Aunt Milaba two thumbs up. “I’m dee-
peeing the diggler.” There was a high-pitched shriek of air being vented into the tanks, a whistle that ebbed into silence as the pressure dropped to match the outside environment. The scribbled-over psuit felt tight and stiff. This was true eyeball-squelch altitude. Then Milaba popped the door and Tash followed her out and down the ladder on to the wild surface of Mars.

  Gods and teeth, but the wind was brutal. Tash balled her fists and squared her shoulders and lowered her head to battle through it to the yellow and blue-chevronned tokamak station. She could feel the sand whipping across the skin of her psuit. She didn’t like to think of the semizoic skin abrading, cell by cell. She imagined it wailing in pain. A tap on the shoulder, Milaba gestured for her to hook her safety line on to the door winch. Then In-Aunt and In-Niece they punched through the big wind to the shelter of the tokamak shell. Out. Out in the world. Up high. If Tash kept walking into the wind she would pass through Windrush Valley and come to a place where the world curved away from her, not towards her. The desire to do it was unbearable. Out of the hole. All it would take would be one foot in front of another. They would take her all the way around the world and back again, to this place. The gale of possibility died. It was all only ever circles. Milaba tapped her again on the shoulder to remind her that there was work to be done here. Tash took the unitool and unscrewed the inspection hatch. Milaba plugged in her diagnosticators. She was glorious to watch at work, easy and absorbed. But it was long work and Tash’s attention wandered to the little meandering dust-dervishes that spun up into a small tornado for a few seconds, staggered down the valley and collapsed into swirling sand.