It did not take long to realize that life inside the Beast was not the essence of excitement, and after checking in with the Sheffield office, and taking a look at the ion chromatograph down in the lab, Art went back out in the rover to have a more extensive look around. This was the way things went when working the Beast, Zafir a.s.sured him; the rovers were like pilot fishes swimming around a great whale, and though the view from the observation deck was nice and high, most people ended up spending a good part of their days out driving around.

So Art did that. The fallen cable out in front of the Beast showed clearly how much harder it had been coming down here than it had back at the start of its fall. Here it was buried to perhaps a third of its diameter, and the cylinder was flattened, and marked by long cracks running along its sides, revealing its structure, which consisted of bundles of bundles of carbon nanotube filament, still one of the strongest substances known to materials science, though apparently the current elevator's cable material was stronger yet.

The Beast straddled this wreckage, about four times as tall as the cable; the charred black semicylinder disappeared into a hole at the front end of the Beast, from which came a grumbling, low, nearly subsonic vibration. And then, every day at about two in the afternoon, a door at the back of the Beast slid open over the tracks always being excreted from the back end of the Beast, and one of the diamond-capped train cars would roll out, winking in the sunlight, and glide off toward Pavonis. The trains disappeared over the high eastern horizon into the apparent "depression" now between him and Pavonis about ten minutes after emerging from their maker.

After viewing the daily departure, Art would take a drive in the pilot-fish rover, investigating craters and big isolated boulders, and, frankly, looking for Nirgal, or rather waiting for him. After a few days of this, he added the habit of suiting up and taking a walk outside for a few hours every afternoon, strolling beside the cable or the pilot fish, or hiking out into the surrounding countryside.

It was odd-looking terrain, not only because of the even distribution of millions of black rocks, but because the hard blanket of firn had been sculpted into fantastic shapes by the sandblaster winds: ridges, boles, hollows, tear-shaped tailings behind every exposed rock, etc.- sastrugi, these shapes were called. It was fun to walk around among these extravagant aerodynamic extrusions of reddish snow.

Day after day he did this. The Beast ground slowly westward. He found that the windswept bare tops of the rocks were often colored by tiny flakes that were scales of fast lichen, a kind that grew quickly, or at least quickly for lichen. Art picked up a couple of sample rocks, and took them back into the Beast, and read about the lichen curiously. These apparently were engineered cryptoendolithic lichens, meaning they lived in rock, and at this alt.i.tude they were living right at the edge of the possible- the article on them said that over ninety-eight percent of their energy was used simply to stay alive, with less than two percent going toward reproduction. And this was a big improvement over the Terran species they had been based on.

More days pa.s.sed, then weeks; but what could he do? He kept on collecting lichen. One of the cryptoendoliths he found was the first species to survive on the Martian surface, the lectern said, and it had been designed by members of the fabled First Hundred. He broke apart some rocks to have a better look, and found bands of the lichen growing in the rocks' outer centimeter: first a yellow stripe right at the surface, then a blue stripe under that, then a green one. After that discovery he often stopped on his walks to kneel and put his faceplate to colored rocks sticking up out of the firn, marveling at the crusty scales and their intense pale colors- yellows, olives, khaki greens, forest greens, blacks, grays.

One afternoon he drove the pilot fish far to the north of the Beast, and got out to hike around and collect samples. When he returned, he found that the lock door in the side of the pilot fish would not open. "What the h.e.l.l?" he said aloud.

It had been so long that he had forgotten that something was supposed to happen. The happening had taken the form of some kind of electronic failure, apparently. a.s.suming that this was the happening, and not... something else. He called in over the intercom, and tried every code he knew on the keypad by the lock door, but nothing had any effect. And since he couldn't get back in, he couldn't turn on the emergency systems. And his helmet's intercom had a very limited range- the horizon, in effect- which down here off Pavonis had shrunk to a Martian closeness, only a few kilometers away in all directions. The Beast was well over the horizon, and though he could probably walk to it, there would be a section of the hike where both Beast and pilot fish would be over the horizon, and himself alone in a suit, with a limited air supply....

Suddenly the landscape with its dirty sastrugi took on an alien, ominous cast, dark even in the bright sunshine. "Well, h.e.l.l;" Art said, thinking hard. He was out here, after all, to get picked up by the underground. Nirgal had said it was going to look like an accident. Of course this was not necessarily that accident, but whether it was or it wasn't, panic was not going to help. Best to make the working a.s.sumption that it was a real problem, and go from there. He could try walking back to the Beast, or he could try getting into the pilot-fish rover.

He was still thinking things over, and typing at the keypad of the lock door like a champion speed-typist, when he was tapped hard on the shoulder. "Aaa!" he shouted, leaping around.

There were two of them, in walkers and scratched old helmets. Through their faceplates he could see them: a woman with a face like a hawk's, who looked like she would be happy to bite him; and a short thin-faced black man, with gray dreadlocks crowding the border of his faceplate, like the rope picture frames one sometimes sees in nautical restaurants.

It was the man who had tapped Art on the shoulder. Now he lifted three fingers, pointing at his wrist console. The intercom band they were using, no doubt. Art switched it on. "Hey!" he cried, feeling more relieved than he ought to, considering that this was probably Nirgal's setup, so that he had never been in danger. "Hey, I seem to be locked out of my car? Could you give me a lift?"

They stared at him.

The man's laugh was scary. "Welcome to Mars," he said.

Part Three

Long Runout

Ann Clayborne was driving down the Geneva Spur, stopping every few switchbacks to get out and take samples from the roadcuts. The Transmarineris Highway had been abandoned after '61, as it now disappeared under the dirty river of ice and boulders covering the floor of Coprates Chasma. The road was an archaeological relic, a dead end.

But Ann was studying the Geneva Spur. The Spur was the final extension of a much longer lava dike, most of which was buried in the plateau to the south. The dike was one of several- the nearby Melas Dorsa, the Felis Dorsa farther east, the Solis Dorsa farther west- all of them perpendicular to the Marineris canyons, and all mysterious in their origin. But as the southern wall of Melas Chasma had receded, by collapse and wind erosion, the hard rock of one dike had been exposed, and this was the Geneva Spur, which had provided the Swiss with a perfect ramp to get their road down the canyon wall, and was now providing Ann with a nicely exposed dike base. It was possible that it and all its companion dikes had been formed by concentric fissuring resulting from the rise of Tharsis; but they could also be much older, remnants of a basin-and-range type spread in the earliest Noachian, when the planet was still expanding from its own internal heat. Dating the basalt at the foot of the dike would help answer the question one way or the other.

So she drove a little boulder car slowly down the frost-covered road. The car's movement would be quite visible from s.p.a.ce, but she didn't care. She had driven all over the southern hemisphere in the previous year, taking no precautions except when approaching one of Coyote's hidden refuges to resupply. Nothing had happened.

She reached the bottom of the Spur, only a short distance from the river of ice and rock that now choked the canyon floor. She got out of the car and tapped away with a geologist's hammer at the bottom of the last roadcut. She kept her back to the immense glacier, and did not think of it. She was focused on the basalt. The dike rose before her into the sun, a perfect ramp to the clifftop, some three kilometers above her and fifty kilometers to the south. On both sides of the Spur the immense southern cliff of Melas Chasma curved back in huge embayments, then out again to lesser prominences- a slight point on the distant horizon to the left, and a ma.s.sive headland some sixty kilometers to the right, which Ann called Cape Solis.

Long ago Ann had predicted that greatly accelerated erosion would follow any hydration of the atmosphere, and on both sides of the Spur the cliff gave indications that she had been right. The embayment between the Geneva Spur and Cape Solis had always been a deep one, but now several fresh landslides showed that it was getting deeper fast. Even the freshest scars, however, as well as all the rest of the fluting and stratification of the cliff, were dusted with frost. The great wall had the coloration of Zion or Bryce after a snowfall- stacked reds, streaked with white.

There was a very low black ridge on the canyon floor, a kilometer or two west of the Geneva Spur, paralleling it. Curious, Ann hiked out to it. On closer inspection the low ridge, no more than chest high, did indeed appear to be made of the same basalt as the Spur. She took out her hammer, and knocked off a sample.

A motion caught her eye and she jerked up to look. Cape Solis was missing its nose. A red cloud was billowing out from its foot.

Landslide! Instantly she started the timer on her wristpad, then knocked the binocular hood down over her faceplate, and fiddled with the focus until the distant headland stood clear in her field of vision. The new rock exposed by the break was blackish, and looked nearly vertical; a cooling fault in the dike, perhaps- if it too was a dike. It did look like basalt. And it looked as if the break had extended the entire height of the cliff, all four kilometers of it.

The cliff face disappeared in the rising cloud of dust, which billowed up and out as if a giant bomb had gone off. A distinct boom was followed by a faint roaring, like distant thunder. She checked her wrist; a little under four minutes. Speed of sound on Mars was 252 meters per second, so the distance of sixty kilometers was confirmed. She had seen almost the very first moment of the fall.

Deep in the embayment a smaller piece of cliff gave way as well, no doubt triggered by shock waves. But it looked like the merest rockfall compared to the collapsed headland, which had to be millions of cubic meters of rock. Fantastic to actually see one of the big landslides- most areologists and geologists had to rely on explosions, or computer simulations. A few weeks spent in Valles Marineris would solve that problem for them.

And here it came, rolling over the ground by the edge of the glacier, a low dark ma.s.s topped by a rolling cloud of dust, like time-lapse film of an approaching thunderhead, sound effects and all. It was really quite a long way out from the cape. She realized with a start that she was witnessing a long runout landslide. They were a strange phenomenon, one of the unsolved puzzles of geology. The great majority of landslides move horizontally less than twice the distance they fall; but a few very large slides appear to defy the laws of friction, running horizontally ten times their vertical drop, and sometimes even twenty or thirty. These were called long runout slides, and no one knew why they happened. Cape Solis, now, had fallen four kilometers, and so should have run out no more than eight; but there it was, well across the floor of Melas, running downcanyon directly at Ann. If it ran only fifteen times its vertical drop, it would roll right over her, and slam into the Geneva Spur.

She adjusted the focus of her binoculars for the front edge of the slide, just visible as a dark churning ma.s.s under the tumbling dustcloud. She could feel her hand trembling against her helmet, but other than that she felt nothing. No fear, no regret- nothing, in fact, but a sense of release. All over at last, and not her fault. No one could blame her for it. She had always said that the terraforming would kill her. She laughed briefly, and then squinted, trying to get a better focus on the front edge of the slide. The earliest standard hypothesis to explain long runouts had been that the rock was riding over a layer of air trapped under the fall; but then old long runouts discovered on Mars and Luna had cast doubts on that notion, and Ann agreed with those who argued that any air trapped under the rock would quickly diffuse upward. There had to be some form of lubricant, however, and other forms proposed had included a layer of molten rock caused by the slide's friction, acoustic waves caused by the slide's noise, or merely the extremely energetic bouncing of the particles caught on the slide's bottom. But none of these were very satisfactory suggestions, and no one knew for sure. She was being approached by a phenomenological mystery.

Nothing about the ma.s.s approaching her under the dustcloud indicated one theory over another. Certainly it wasn't glowing like molten lava, and though it was loud, there was no way of judging whether it was loud enough to be riding on its own sonic boom. On it came in any case, no matter what the mechanism. It looked as though she was going to get a chance to investigate in person, her last act a contribution to geology, lost in the moment of discovery.

She checked her wrist, and was surprised to see that twenty minutes had pa.s.sed already. Long runouts were known to be fast; the Blackhawk slide in the Mojave was estimated to have traveled at 120 kilometers per hour, going down a slope of only a couple of degrees. Melas was in general a bit steeper than that. And indeed the front edge of the slide was closing fast. The noise was getting louder, like rolling thunder directly overhead. The dustcloud reared up, blocking out the afternoon sun.

Ann turned and looked out at the great Marineris glacier. She had almost been killed by it more than once, when it was an aquifer outbreak flooding down the great canyons. And Frank Chalmers had been killed by it, and was entombed somewhere in its ice, far downstream. His death had been caused by her mistake, and the remorse had never left her. It had been a moment of inattention only, but a mistake nevertheless; and some mistakes you never can make good.

And then Simon had died too, engulfed in an avalanche of his own white blood cells. Now it was her turn. The relief was so acute it was painful.

She faced the avalanche. The rock visible at the bottom was bouncing, it seemed, but not rolling over itself like a broken wave. Apparently it was indeed riding over some kind of lubricating layer. Geologists had found nearly intact meadows on top of landslides that had moved many kilometers, so this was confirmation of something known, but it certainly did look peculiar, even unreal: a low rampart advancing across the land without a rollover, like a magic trick. The ground under her feet was vibrating, and she found that her hands were clenched into fists. She thought of Simon, fighting death in his last hours, and hissed; it seemed wrong to stand there welcoming the end so happily, she knew he would not approve. As a gesture to his spirit she stepped off the low lava dike and went down onto one knee behind it. The coa.r.s.e grain of its basalt was dull in the brown light. She felt the vibrations, looked up at the sky. She had done what she could, no one could fault her. Anyway it was foolish to think that way; no one would ever know what she did here, not even Simon. He was gone. And the Simon inside her would never stop hara.s.sing her, no matter what she did. So it was time to rest, and be thankful. The dustcloud rolled over the low dike, there was a wind- Boom! She was thrown flat by the impact of the noise, picked up and dragged over the canyon floor, thrown and pummeled by rock. She was in a dark cloud, on her hands and knees, dust all around her, the roar of gnashing rock filling everything, the ground tossing underfoot like a wild thing....

The jostling subsided. She was still on her hands and knees, feeling the cold rock through her gloves and kneepads. Gusts of wind slowly cleared the air. She was covered with dust, and small fragments of stone.

Shakily she stood. Her palms and knees hurt, and one kneecap was numb with cold. Her left wrist felt the stab of a sprain. She walked up to the low dike, looked over it. The landslide had stopped about thirty meters short of the dike. The ground in between was littered with rubble, but the edge of the slide proper was a black wall of pulverized basalt, sloping back at about a forty-five-degree angle, and twenty or twenty-five meters tall. If she had stayed standing on the low dike, the impact of the air would have thrown her down and killed her. "G.o.dd.a.m.n you," she said to Simon.

The northern border of the slide had run out onto the Melas glacier, melting the ice and mixing with it in a steaming trough of boulders and mud. The dustcloud made it hard to see much of that. Ann crossed the dike, walked up to the foot of the slide. The rocks at the bottom of it were still hot. They seemed no more fractured than the rock higher in the slide. Ann stared at the new black wall, her ears ringing. Not fair, she thought. Not fair.

She walked back to the Geneva Spur, feeling sick and dazed. The boulder car was still on the dead-end road, dusty but apparently unharmed. For the longest time she could not bear to touch it. She stared back over the long smoking ma.s.s of the slide- a black glacier, next to a white one. Finally she opened the lock door and ducked inside. There was no other choice.

Ann drove a little every day, then got out and walked over the planet, doing her work doggedly, like an automaton.

To each side of the Tharsis bulge there was a depression. On the west side was Amazonis Planitia, a low plain reaching deep into the southern highlands. On the east was the Chryse Trough, a depression that ran from the Argyre Basin through the Margaritifer Sinus and Chryse Planitia, the deepest point in the trough. The trough was an average of two kilometers lower than its surroundings, and all the chaotic terrain on Mars, and most of the ancient outbreak channels, were located in it.

Ann drove east along the southern rim of Marineris, until she was between Nirgal Vallis and the Aureum Chaos. She stopped to resupply at the refuge called Dolmen Tor, which was where Michel and Kasei had taken them at the end of their retreat down Marineris, in 2061. Seeing the little refuge again did not affect her; she scarcely remembered it. All her memories were going away, which she found comforting. She worked at it, in fact, concentrating on the moment with such intensity that even the moment itself went away, each instant a burst of light in a fog, like things breaking in her head.

Certainly the trough predated the chaos and the outbreak channels, which were no doubt located there because of the trough. The Tharsis bulge had been a tremendous source of outga.s.sing from the hot center of the planet, all the radial and concentric fractures around it leaking volatiles out of the hot center of the planet. Water in the regolith had run downhill, into the depressions on each side of the bulge. It could be that the depressions were the direct result of the bulge, simply a matter of the lithosphere bent down on the outskirts of where it had been pushed up. Or it could be that the mantle had sunk underneath the depressions, as it had plumed under the bulge. Standard convection models would support such an idea- the upwelling of the plume had to go back down somewhere, after all, rolling at its sides and pulling the lithosphere down after it.

And then, up in the regolith, water had run downhill in its usual way, pooling in the troughs, until the aquifers burst open, and the surface over them collapsed: thus the outbreak channels, and the chaos. It was a good working model, plausible and powerful, explaining a lot of features.

So every day Ann drove and then walked, seeking confirmation of the mantle convection explanation for the Chryse trough, wandering over the surface of the planet, checking old seismographs and picking away at rocks. It was hard now to make one's way north in the trough; the aquifer outbreaks of 2061 nearly blocked the way, leaving only a narrow slot between the eastern end of the great Marineris glacier and the western side of a smaller glacier that filled the whole length of Ares Vallis. This slot was the first chance east of Noctis Labyrinthus to cross the equator without going over ice, and Noctis was six thousand kilometers away. So a piste and a road had been built in the slot, and a fairly large tent town established on the rim of Galilaei Crater. South of Galilaei the narrowest part of the slot was only forty kilometers wide, a zone of navigable plain located between the eastern arm of the Hydaspis Chaos and the western part of Aram Chaos. It was hard to drive through this zone and keep the piste and road under the horizons, and Ann drove right on the edge of Aram Chaos, looking down onto the shattered terrain.

North of Galilaei it was easier. And then she was out of the slot, and onto Chryse Planitia. This was the heart of the trough, with a gravitational potential of -0.65; the lightest place on the planet, lighter even than h.e.l.las and Isidis.

But one day she drove onto the top of a lone hill, and saw that there was an ice sea out in the middle of Chryse. A long glacier had run down from Simud Vallis and pooled in the Chryse low point, spreading until it became an ice sea, covering the land over the horizons to north, northeast, northwest. She drove slowly around its western sh.o.r.e, then its northern sh.o.r.e. It was some two hundred kilometers across.

Near the end of one day she stopped her car on a ghost crater rim, and stared out across the expanse of broken ice. There had been so many outbreaks in '61. It was clear that there had been some good areologists working for the rebels in those days, finding aquifers and setting off explosions or reactor meltdowns precisely where the hydrostatic pressures were the greatest. Using a lot of her own findings, it seemed.

But that was the past, banished now. All that was gone. Here and now, there was only this ice sea. The old seismographs she had picked up all had records disturbed by recent temblors from the north, where there should have been very little activity. Perhaps the melting of the northern polar cap was causing the lithosphere there to rebound upward, setting off lots of small marsquakes. But the temblors recorded by the seismographs were discrete short-period shocks, like explosions rather than marsquakes. She had studied her car's AI screen through many a long evening, mystified.

Every day she drove, then walked. She left the ice sea, and continued north onto Acidalia.

The great plains of the northern hemisphere were generally referred to as level, and they certainly were compared to the chaoses, or to the southern highlands. But still, they were not level like a playing field or a table top- not even close. There were undulations everywhere, a continuous up-and-downing of hummocks and hollows, ridges of cracking bedrock, hollows of fine drifts, great rumpled boulder fields, isolated tors and little sinkholes... It was unearthly. On Earth, soil would have filled the hollows, and wind and water and plant life would have worn down the bare hilltops, and then the whole thing would have been submerged or subducted or worn flat by ice sheets, or uplifted by tectonic action, everything torn away and rebuilt scores of times as the eons pa.s.sed, and always flattened by weather and biota. But these ancient corrugated plains, their hollows banged out by meteor impact, had not changed for a billion years. And they were among the youngest surfaces on Mars.

It was a hard thing to drive across such lumpy terrain, and very easy to get lost when out walking, particularly if one's car looked just like all the other boulders scattered about; particularly if one was distracted. More than once Ann had to find the car by radio signal rather than visual sighting, and sometimes she walked right up to it before recognizing it- and then would wake up, or come to, hands shaking in the aftershock of some forgotten reverie.

The best driving routes were along the low ridges and dikes of exposed bedrock. If these high basalt roads had connected one to the next, it would have been easy. But they commonly were broken by transverse faults, at first no more than line cracks, which then got deeper and wider as one progressed, in sequences like loaves of sliced bread tipping open, until the faults gaped and were filled with rubble and fines, and the dike became nothing but part of a boulder field again.

She continued north, onto Vast.i.tas Borealis. Acidalia, Borealis: the old names were so strange. She was doing her best never to think, but during the long hours in the car it was sometimes impossible not to. At those times it was less dangerous to read than it was to try staying blank. So she would read randomly in her AI's library. Often she ended up staring at areological maps, and one evening at sunset after such a session, she looked into this matter of Mars's names.

It turned out most of them came from Giovanni Schiaparelli. On his telescope maps he had named over a hundred albedo features, most of which were just as illusory as his ca.n.a.li ca.n.a.li. But when the astronomers of the 1950s had regularized a map of the albedo features everyone could agree on- features that could be photographed- many of Schiaparelli's names had been retained. It was a tribute to a certain power he had had, a power evocative if not consistent; he had been a cla.s.sical scholar, and a student of biblical astronomy, and among his names there were Latin, Greek, biblical, and Homeric references, all mixed together. But he had had a good ear, somehow. One proof of his talent was the contrast between his maps and the competing Martian maps of the nineteenth century. A map by an Englishman named Proctor, for instance, had relied on the sketches of a Reverend William Dawes; and so on Proctor's Mars, which had no recognizable relations even to the standard albedo features, there was a Dawes Continent, a Dawes Ocean, a Dawes Strait, a Dawes Sea, and a Dawes Forked Bay. Also an Airy Sea, a DeLaRue Ocean, and a Beer Sea. Admittedly this last was a tribute to a German named Beer, who had drawn a Mars map even worse than Proctor's. Still, compared to them Schiaparelli had been a genius.

But not consistent. And there was something wrong in this melange of references, something dangerous. Mercury's features were all named after great artists, Venus's were named after famous women; they would drive or fly over those landscapes one day, and feel that they lived in coherent worlds. Only on Mars did they walk about in a horrendous mishmash of the dreams of the past, causing who knew what disastrous misapprehensions of the real terrain: the Lake of the Sun, the Plain of Gold, the Red Sea, Peac.o.c.k Mountain, the Lake of the Phoenix, Cimmeria, Arcadia, the Gulf of Pearls, the Gordian Knot, Styx, Hades, Utopia....

On the dark dunes of Vast.i.tas Borealis she began to run low on supplies. Her seismographs showed daily temblors to the east, and she drove toward them. On her walks outside she studied the garnet sand dunes, and their layering, which revealed the old climates like tree rings. But snow and high winds were tearing off the crests of the dunes. The westerlies could be extremely strong, enough to pick up sheets of large-grained sand and hurl them against her car. The sand would always settle in dune formations, as a simple matter of physics, but the dunes would be picking up the pace of their slow march around the world, and the record they had made of earlier ages would be destroyed.

She forced that thought from her mind, and studied the phenomenon as if there were no new artificial forces disturbing it. She focused on her work as if clenching her geologist's hammer, as if breaking apart rocks. The past was spalled away piece by piece. Leave it behind. She refused to think of it. But more than once she jerked out of sleep with the image of the long runout coming at her. And then she was awake for good, sweating and trembling, faced with the incandescent dawn, the sun blazing like a chunk of burning sulphur.

Coyote had given her a map of his caches in the north, and now she came to one buried in a cl.u.s.ter of house-sized boulders. She restocked, leaving a brief thank-you note. The last itinerary Coyote had given her said he was going to be dropping by this area sometime soon, but there was no sign of him, and no use waiting. She drove on.

She drove, she walked. But she couldn't help it; the memory of the landslide haunted her. What bothered her was not that she had had a brush with death, which no doubt had happened many times before, mostly in ways she had not noticed. It was simply how arbitrary it had been. It had nothing to do with value or fitness; it was pure contingency. Punctuated equilibrium, without the equilibrium. Effects did not follow from causes, and one did not get one's just desserts. She was the one who had spent too much time outdoors, after all, taking on far too much radiation; but it was Simon who had died. And she was the one who had fallen asleep at the wheel; but it was Frank who had died. It was simply a matter of chance, of accidental survival or erasure.

It was hard to believe natural selection had made any way in such a universe. There under her feet, in the troughs between the dunes, archaebacteria were growing on sand grains; but the atmosphere was gaining oxygen fast, and all the archaebacteria would die out except those that were by accident underground, away from the oxygen they themselves had respired, the oxygen that was poisonous to them. Natural selection or accident? You stood, breathing gases, while death rushed toward you- and were covered by boulders, and died, or covered by dust, and lived. And nothing you did mattered in that great either-or. Nothing you did mattered. One afternoon, reading randomly in the AI to distract herself between her return to the car and her dinner hour, she learned that the Czarist police had taken Dostoyevsky out to be executed, and only brought him back in after several hours of waiting for his turn. Ann finished reading about this incident and sat in the driver's seat of her car, feet on the dash, staring at the screen blindly. Another garish sunset poured through the window over her, the sun weirdly large and bright in the thickening atmosphere. Dostoyevsky had been changed for life, the writer declared in the easy omniscience of biography. An epileptic, p.r.o.ne to violence, p.r.o.ne to despair. He hadn't been able to integrate the experience. Perpetually angry. Fearful. Possessed.

Ann shook her head and laughed, angry at the idiot writer, who simply didn't understand. Of course you didn't integrate the experience integrate the experience. It was meaninglessness. The experience that couldn't be integrated.

The next day a tower poked over the horizon. She stopped the car, stared at it through the car's telescope. There was a lot of ground mist behind it. The temblors registering on her seismograph were very strong now, and appeared to be coming from a bit to the north. She even felt one of them herself, which, given the car's shock absorbers, meant they were strong indeed. It seemed likely there was a connection with the tower.

She got out of her car. It was almost sunset, the sky a great arch of violent colors, the sun low in the hazy west. The light would be behind her, making her very hard to see. She wound between dunes, then carefully made her way to the crest of one, and crawled the final meters of the way, and looked over the crest at the tower, now only a kilometer to the east. When she saw how close its base was she kept her chin right on the ground, among ejecta the size of her helmet.

It was some kind of mobile drilling operation, a big one. The ma.s.sive base was flanked by giant caterpillar tracks, like those used to move the largest rockets around a s.p.a.ceport. The drill tower rose out of this behemoth more than sixty meters, and the base and lower part of the tower clearly contained the technicians' housing and equipment and supplies.

Beyond this thing, a short distance down a gentle slope to the north, was a sea of ice. Immediately north of the drill, the crests of the great barchan dunes still stuck out of the ice- first as a b.u.mpy beach, then as hundreds of crescent islands. But a couple of kilometers out the dune crests disappeared, and it was ice only.

The ice was pure, clean- translucent purple under the sunset sky- clearer than any ice she had ever seen on the Martian surface, and smooth, not broken like all the glaciers. It was steaming faintly, the frost steam whipping east on the wind. And out on it, looking like ants, people in walkers and helmets were ice-skating.

It came clear the moment she saw the ice. Long ago she herself had confirmed the big impact hypothesis, which accounted for the dichotomy between the hemispheres: the low smooth northern hemisphere was simply a superhuge impact basin, the result of a scarcely imaginable collision in the Noachian, between Mars and a planetesimal nearly as big as it. The rock of the impact body that had not vaporized had become part of Mars itself, and there were arguments in the literature that the irregular movements in the mantle that had caused the Tharsis bulge were late developments resulting from perturbations originating with the impact. To Ann that wasn't likely, but what was clear was that the great crash had happened, wiping out the surface of the entire northern hemisphere, and lowering it by an average of four kilometers relative to the south. An astonishing hit, but that was the Noachian. An impact of similar magnitude had in all probability caused the birth of Luna out of Earth. In fact there were some anti-impact holdouts arguing that if Mars had been hit as hard, it should have had a moon as big.

But now, as she lay flat looking at the giant drilling rig, the point was that the northern hemisphere was even lower than it first appeared, for its floor of bedrock was amazingly deep, as much as five kilometers beneath the surface of the dunes. The impact had blown that deep, and then the depression had mostly refilled, with a mixture of ejecta from the big impact, windblown sand and fines, later impact material, erosional material sliding down the slope of the Great Escarpment, and water. Yes, water, finding the lowest point as it always did; the water in the annual frost hood, and the ancient aquifer outbreaks, and the outga.s.sing from the blistered bedrock, and the lensing from the polar cap, had all eventually migrated to this deep zone, and combined to form a truly enormous underground reservoir, an ice and liquid pool that extended in a band all the way around the planet, underlying almost everything north of 60 north lat.i.tude, except, ironically, for a bedrock island on which the polar cap itself stood.

Ann herself had discovered this underground sea many years before, and by her estimates between sixty and seventy percent of all the water on Mars was down there. It was, in fact, the Ocea.n.u.s Borealis that some terraformers talked about- but buried, deeply buried, and mostly frozen, and mixed with regolith and dense fines; a permafrost ocean, with some liquid down on the deepest bedrock. All locked down there for good, or so she had thought, because no matter how much heat the terraformers applied to the planet's surface, the permafrost ocean would not thaw much faster than a meter per millennium- and even when it did melt it would remain underground, simply as a matter of gravity.

Thus the drilling rig before her. They were mining the water. Mining the liquid aquifers directly, and also melting the permafrost with explosives, probably nuclear explosives, and then collecting the melt and pumping it onto the surface. The weight of the overlying regolith would help push the water up through pipes. The weight of water on the surface would help push up more. If there were very many drilling rigs like this one, they could put a tremendous amount on the surface. Eventually they would have a shallow sea. It would refreeze and become an ice sea again for a while, but between atmospheric warming, sunlight, bacterial action, increasing winds- it would melt again, eventually. And then there would be an Ocea.n.u.s Borealis. And the old Vast.i.tas Borealis, with its world-wrapping black garnet dunes, would be sea bottom. Drowned.

She walked back to her car in the twilight, moving clumsily. It was difficult to operate the locks, to get her helmet off. Inside she sat before the microwave without moving for more than an hour, images flitting through her mind. Ants burning under a magnifying gla.s.s, an anthill drowned behind a mud dam.... She had thought that nothing could reach her anymore in this preposthumous existence she was living- but her hands trembled, and she could not face the rice and salmon cooling in the microwave. Red Mars was gone. Her stomach was a small stone in her body. In the random flux of universal contingency, nothing mattered; and yet, and yet....

She drove away. She couldn't think of anything else to do. She returned south, driving up the low slopes, past Chryse and its little ice sea. It would be a bay of the larger ocean, eventually. She focused on her work, or tried. She fought to see nothing but rock, to think like a stone.

One day she drove over a plain of small black boulders. The plain was smoother than usual, the horizon its usual five kilometers away, familiar from Underhill and all the rest of the lowlands. A little world, and completely filled with small black boulders, like fossil b.a.l.l.s from various sports, only all black, and all faceted to one extent or another. They were ventifacts.

She got out of the car to walk around and look. The rocks drew her on. She walked a long way west.

A front of low clouds rolled over the horizon, and she could feel the wind pushing at her in gusts. In the premature dark of the suddenly stormy afternoon, the boulder field took on a weird beauty; she stood in a slab of dim air, rushing between two planes of lumpy blackness.

The boulders were basalt rocks, which had been scoured by the winds on one exposed surface, until that surface had been sc.r.a.ped flat. Perhaps a million years for that first sc.r.a.ping. And then the underlying clays had been blown away, or a rare marsquake had shaken the region, and the rock had shifted to a new position, exposing a different surface. And the process had begun again. A new facet would be slowly sc.r.a.ped flat by the ceaseless brushing of micron-sized abrasives, until once again the rock's equilibrium changed, or another rock b.u.mped it, or something else shifted it from its position. And then it would start again. Every boulder in that field, shifting every million years or so, and then lying still under the wind for day after day, year after year. So that there were einkanters einkanters with single facets, and with single facets, and dreikanters dreikanters with three facets- with three facets-fierkanters, funfkanters- all the way up to nearly perfect hexahedrons, octahedrons, dodecahedrons. Ventifacts. Ann hefted one after another of them, thinking about how many years their planed sides represented, wondering whether her mind might not reveal similar scourings, big sections worn flat by time.

It began to snow. First swirling flakes, then big soft blobs, pouring down on the wind. It was relatively warm out, and the snow was slushy, then sleety, then an ugly mix of hail and wet snow, all flailing down in a hard wind. As the storm progessed, the snow became very dirty; apparently it had been pushed up and down in the atmosphere for a long time, collecting fines and dust and smoke particulates, and crystallizing more moisture and then flying up on another updraft in the thunderhead to do it again, until what came down was nearly black. Black snow. And then it was a kind of frozen mud that was falling, filling in the holes and gaps between the ventifacts, coating their tops, then dropping off their sides, as the keening wind caused a million little avalanches. Ann staggered aimlessly, pointlessly, until she twisted an ankle and stopped, her breath racking in and out of her, a rock clutched in each cold gloved hand. She understood that the long runout was running still. And mud snow pelted down out of the black air, burying the plain.

But nothing lasts, not even stone, not even despair.

Ann got back to her car, she didn't know how or why. She drove a little every day, and without consciously intending to, came back to Coyote's cache. She stayed there for a week, walking over the dunes and mumbling her food.

Then one day: "Ann, di da do?"

She only understood the word Ann Ann. Shocked at the return of her glossolalia, she put both hands to the radio speaker, and tried to talk. Nothing came out but a choking sound.

"Ann, di da do?"

It was a question.