Mars Plus

Chapter 1 She'll Be Coming Down the Fountain When She Comes

Demeter Coghlan plunged toward Mars in a blaze of glory.

The tiny passenger pod attached to the space fountain fell at an acceleration of 3.72 meters per second squared, at a rate equal to the pull of Mars's gravity. At this stage of her eight-hour descent from geosynchronous—or was that areosynchronous?—orbit down to the planet's surface, the dynamic braking of the car's magnetic couplings restrained her hardly at all. No more, really, than a shuttle rocket in reentry mode.

Coghlan s understanding of the underlying physics of the Hyde Industries, Inc. fountain technology was sketchy at best. Somewhere along the equator near a place called Tharsis Montes, a linear accelerator stood upright at the bottom of a well dug deep under the Martian surface. The accelerator shot a series of ferrite hoops, each a meter in diameter and weighing almost a kilogram apiece, straight up into the sky. Moving at some tens of kilometers per second, this fountain of objects created a tremendous kinetic energy. At the upper end of their flight, the hoop-stream entered an electromagnetic torus that functioned like the pulley wheel in a sheave block: bending the stream back on itself to descend at gravitationally increasing speeds toward the planet s surface. There the stream entered another torus which passed it across to the accelerator again, completing a closed loop of flying rings.

The system resembled a chainsaw held together by the forces of inertia and magnetism.

The impact of a gazillion of these iron rings against the magnetic field of the top block had originally boosted it—and the freight-transfer station built around it—high into the Martian sky. The top of the fountain extended from the well at Tharsis Montes almost up to synchronous orbit. As the top station had sailed aloft during the initial stages of construction, the engineers fabricated and attached a series of collapsible shells to its lower perimeter, enclosing the ever-lengthening stream against random winds at ground level and providing spaced magnetic deflectors that nudged the higher segments eastward to counteract the planets Coriolis forces.

In those early stages, bringing the hoop-stream up to speed had consumed nine-tenths of the systems energy. The flying rings had consumed whole quads of electricity, enough to drive the industrial sector of a fair-sized moon. That initial input had come from a cloverleaf of solar farms and fission piles constructed on the planet's surface for this purpose. Once the operation was balanced, however, it required only minor additions of maintenance energy to stabilize the stream and the structures it supported against the pull of Mars's gravity. The power plants could then be diverted to serve other needs in the local economy.

The fountain only required small inputs to replace the minuscule amounts of kinetic energy that the freight handlers bled off in the form of electricity. They used this current to pass cargo and passenger pods to and from the interplanetary ships that crossed above the tower in intersecting orbits. The electricity also worked mass drivers, which pushed goods and people up and down the exterior tower shell between the top station and the surface.

Although the system had cost billions of Neumarks to build and power up, it now saved as much or more ever year in the costs of rocket propellant and hull ablation—not to mention the occasional pyrotechnic tragedies—associated with orbital shuttles. Being wholly electric in operation, the Tharsis Montes Space Fountain was as quiet, non-polluting, and safe to ride as a trolley. In principle and structure this system copied the Earth-based fountains operated by the U.N. at Porto Santana, Brazil; Kismayu, Somalia; and Bukit-tingi, Indonesia. Like Tharsis Montes, these were all on the planets equator and served geostationary transit points, although the technology worked at all altitudes and at any latitude; the small fountain at Tsiolkovskii, for example, was nowhere near the Moon's equator.

Although the Mars fountain's supporting stream of flying rings was silent and vibrationless in operation, their iron composition did induce momentary currents in the tower's metallic superstructure. These showed up as ionization along its outer surfaces. Against the star-filled blacks of" space surrounding the tower's upper segments, Demeter sensed an aura of plum-colored light at the periphery of her vision. But as she neared the planet's surface and entered what remained of Mars s indigenous atmosphere, the blacks faded to salmon pink and the glow dimmed to a patina of lilac over the gray of finished steel.

Her mothers colors.

Despite the massive energies involved in erecting and maintaining the space fountain, at this point in her trip Demeter Coghlan was still essentially in freefall, after seven months of microgravity on the transport ship coming up from Earth. Looking out the viewport past the purple mists of atmospheric ionization, she was barely conscious that she floated on her stomach with her heels higher than her head. Demeter didn't at all mind a few more hours of swimming weightlessness; she was just glad she could finally give up those mandatory three hours of osteopathic exercise per ship's day. Demeter hated jogging on the wheel with her arms and legs strapped into spring-weights—even if the workout had taken off thirteen pounds of cellulite that she really could afford to lose.

Craning her neck, and pressing her cheek against the cold glass—or whatever clear laminate they used for pressure windows here—she tried to look down and see the base of the fountain. The column of violet light seemed to touch the ground in the wide caldera of a shallow lava cone. Coghlan thought this was Olympus Mons itself but decided to query that fact with her personal chrono, which tied into the local computer grid whenever it could. Certainly the fountains transit pod would have an RF antenna in the walls or something for the convenience of passengers and their cyber servants.

"Hey, Sugar!" Demeter whispered into the titanium bauble on her bracelet. "What's that-there volcano I'm looking at?"

"Could y'all be a tad more specific, Dem?" came back the pearly voice with the Annie Oakley twang she'd programmed into its microchips.

"Well, I'm riding the space fountain on Mars, y'see, and we're just about at the bottom. There's this big crater right below us—I thought maybe Olympus Mons, you know? Looks like it could be, oh, sixty or eighty klicks in diameter, with an ash cone maybe five or six times that wide. So, is this an important piece of real estate or what?"

"Please wait." The lag must have been mere microseconds, because Sugar spoke again almost at once. "Regretfully, I can establish 110 interconnect with network resources. Electromagnetic interference inherent to the operation of Hyde Industries' space elevators must be blocking my radio signals. However, knowing that we were going to Mars, I did pack some general history and geography into spare memory. Want to hear it?"

"Go on ahead."

"Olympus Mons—with a diameter of six hundred kilometers and an elevation of twenty-six, the Solar System s largest volcano—is located at twenty degrees north latitude. That would be almost twelve hundred kilometers from your present position. I doubt even the southern shield of the Olympus trap rock would be visible from your current elevation on the fountain's lower structure. On the other hand, the transaction coil for the Mars elevator is based at one-hundred-twelve degrees west longitude, zero degrees latitude, adjacent to the population center known as Tharsis Montes. That is the second-largest tunnel complex built by Earths colonists to date."

"I already know that, Sugar."

"Ahh, right.... So, the nearest natural feature of any prominence is Pavonis Mons, with a height of twenty-one kilometers. This is one of the largest calderas of the Tharsis Ridge. After accounting for variables like pod elevation, atmospheric density, and probable dust-storm activity, I deduce this to be the cone you-all are describing, Dem. Chance of error is less than twenty percent."

Coghlan summed up. "Okay, so Tharsis Montes is the name for the colony—"

"And this whole volcanic plateau," Sugar put in.

"—while Pavonis is the big crater. Got you. Thanks, Sugar."

"No never mind, Dem."

Ever since her accident, Demeter Coghlan had placed certain operating restrictions on her chrono. For one thing, she had voice-programmed it with a persistent courtesy, rendered in such null phrases as "please" and "never mind." That didn't make Sugar any more human, but Coghlan found it easier to relate to a machine that talked like one. For another, she had limited the unit's on-line access to the planetwide computer grid. Consequently, Sugar had to announce where she was getting her data from and the probability for error in any calculation—something most cybers omitted in talking to humans these days. As a third precaution, whenever Coghlan went to bed she put Sugar and her charm bracelet in a drawer or under a water glass. That way, the device wouldn't pick up anything she might say in her sleep and report it back-to the grid. Probably paranoid behavior on her part, but all the same it made Coghlan feel better.

Demeter now had little to do but watch the crater rise out of the Martian plain, coming up like an ancient puckered mouth to kiss the descending pod. She had the vehicle practically to herself, having boarded it between the rush of docking transports. Aside from several containers marked fragile, which could not withstand the forced drop of a freight pod, there were only two other passengers.

One was a dark-skinned gentleman in a sea-green turban and knotted beard who spoke no English, strapped himself tightly into one of the contour seats against the suspension of microgravity, and haughtily immersed himself in the shimmering holos of a news-board. Occasionally he grimaced and grunted over the stories. Looking across the pod and reading in reverse through the projected page, Demeter could make out the masthead as The New Delhi Deliverancer, with an angry lion worked into the Old English lettering. All the rest was in some cursive script she thought might be Hindi.

The other passenger was a woman, fair-skinned with streaky blond hair, who wore a slinky metallic sarong that reminded Demeter of the South Seas. It had an embroidered slit up the right side that bared one pale and pimply hip; the loose fabric fluttered in the weightlessness and drafts from the cabin's ventilation system. The woman's only ornaments were a round, garnet-colored scar above her sparse brows and a large blue tear tattooed at the outside corner of each eve.

Early on, Demeter had tried to engage her in conversation, but none of the languages Coghlan had practiced at school—Diplomatic English, Universalniy Russkovo, Mex-Tecan Spanish, or Classical Arabic— seemed to work. The blonde just shrugged and smiled a lot, in between tucking her sarong tighter around her knees against the Sikh's covert glances.

Demeter kept on her solitary sightseeing with the crater growing larger below her all the time. Just when it seemed about to swallow the pod whole, the rim's outside edge shot up past the viewport. Coghlan was left staring at a long slope of weathered, gray rocks.

A few seconds later the floor began rising under her. First her toes, then her knees dropped to the carpeted surface, then her outstretched hand settled in among the seat cushions. After months of free-floating ease, she suddenly had to support her own weight against gravity. The pressure grew heavier as the pod's descent slowed—although even Demeter knew without Sugar's telling her that the surface gravity would never reach much more than a third of Earth normal.

With a bump that threw her down on one elbow, the pod touched down on Mars.

The window showed a curved face of machine-smoothed rock, illuminated by work lights set at odd angles. Immediately she heard and felt the click! and clatter! of grapples locking onto and stabilizing the pod, of power leads connecting to its batteries, and the airlock mating with its exit port. After a few seconds, the door slid upward. Demeter s ears popped with the difference in pressure, the tunnel complex being maintained at a slightly lower ambient.

Coghlan glanced at her two fellow passengers, but they were busy gathering themselves for departure. She straightened her one-piece, wine-colored jumper, draped her nysilk scarf artfully over her shoulders, and plucked her two pieces of luggage from under the restraining straps—noting how light the bulky, soft-plastic carryalls felt in point-three-eight gee—and marched out ahead of them.

In the narrow, steel-paneled passageway outside there was no one to meet or direct her. Officially, Demeter was on vacation. Grandaddy Coghlan had thought she needed something new and exciting— certainly not more course work in dry subjects like Practical Negotiation, Boolean Economics, or Cultural Apperception and Assimilation—not after she had just finished nine months of physical and psychological therapy, learning to use her brand-new, vat-grown, rebuilt brains. "Go to Mars, why don't you?" he had urged. "See the frontier, ride a proxy, shoot a wild thorax or whatever." G'dad Coghlan could easily arrange the transit fees and residence permits, too, being Vice President of the Sovereign State of Texahoma. And so Demeter had done just that, taken a vacation ... with a few strings attached.

It was because of those strings that she expected someone to meet her discreetly at the fountain stop and at least carry her bags.

Down at the far end of the corridor—where it teed into a wider tunnel, this one faced with white tiles— she saw someone moving away.

"Hey there! Y'all got any—"

She came up short and dropped her luggage. Her voice, even to her own ears as modulated by masses of throat muscle and cubic centimeters of sinus cavity, had come out high and squeaky. Something like "Hee thir! Y'eel get eeeny—" Minnie Mouse skyrocketing on amphetamines.

Demeter grabbed her left wrist and ducked her head to put the titanium bangle close to her lips. "Sugar! What's happening to me?" she husked—and it still sounded like a screech. "I'm hyperventilating or something—"

"Wait one," the cyber said impassively. "Pulse normal, considering your elevated stress level. Respiration normal, ditto. Blood sugar and electrolytes all check out. O-two content is slightly high, though. Why do you think you're in trouble, Dem?"

"Listen to my voice!" Coghlan squealed.

"Wait one. . . . The Mars grid informs me that the inhabited tunnels are normally pressurized with twenty percent diatomic oxygen, seventy-nine percent diatomic helium, and traces of carbon dioxide, water vapor, hydrogen sulfide, formaldehyde, and other organic compounds residual to human respiration and industrial pollution."

"Why the high content of helium?" Demeter asked, curious.

"This inert gas replaces the proportion represented by nitrogen in Earths atmosphere. Nitrogen is only marginally present on Mars, either in the atmosphere—two-point-seven percent—or bound up in the lithosphere. All recovered amounts are required to be introduced into the soil for improved crop yields. Consequently, the colonists supplement their habitat pressure with helium, which they draw off as a by-product of methane collection from deep wells. . . . I have four-point-two megabytes of supplementary data on the planets gas industry and eight gigabytes of introductory material on tunnel ecology and the algorithms governing environmental balance. Do you want to hear them?"

"Some other time."

"Never no mind, Dem."

Demeter Coghlan drew a deep breath, calmed down, and decided that the air tasted like any of the canned stuff she'd been inhaling since she got up to low Earth orbit. It would pass for breathable, but it sure wasn't a Texas alfalfa field on a June morning.

By now the man at the end of the corridor was long gone. Demeter was vaguely aware that sometime during Sugar's dissertation on atmosphere composition the Sikh and the South Seas girl had pushed past her. She would have to hurry and get herself processed before the next wave of tourists arrived down the fountain.

At the tee junction she found another Martian, several of them in fact, all striding purposefully about their business.

"Excuse me," she wheezed. "Where do I check in?" ... Cheek een?

One of them turned and pointed to a sign. "Anywhere," the man whistled. Eeneeiveer....

The sign said: arriving casuals (non-resident aliens) please announce yourself to the grid for further instructions.

Demeter raised the silvery patinaed bead to her lips again. "Sugar, get me in touch with the local grid, will you? It seems I need to clear my passport or something."

"Sorry, Dem, no can do," the chrono replied after a milliseconds hesitation. "The grid wants you on one of its wired-in terminals. Something about giving them a thumbprint."

"Okay... which way?"

"Should be a terminal in the wall to your left."

Demeter looked, saw only a dozen meters of white tile. "Nothing there, Shoogs."

"Oh, sorry! Thought we were facing south. Your other left, then."

Coghlan turned around and found, about five meters down, a shelf with a keyboard and screen. The screen was blinking an empty moire pattern. "Got it."

Demeter went up to the public terminal and studied the layout. On the shelf to the right of the board was a trackball; to the left was a contact pad for taking and BlOSing neural patches; and below was a two-handed glovebox. Theoretically, she could control a limited virtual reality from this spot—if the cybers would let her. She stepped up to the shelf, evidently breaking a proximity line somewhere.

The screen changed to: please enter your full name or citizen code, and thumrprint in six different languages. The top line, she noted, was in Diplomatic English.

She typed in her name and laid her thumb on the pad.

"Welcome to Mars, Ms. Coghlan," the cyber said in colloquial Texahoman English—but pitched to the high squeak of a human voice on helium. Meanwhile the screen displayed tourist stills of the Martian landscape and tunnel habitat that vaguely matched the ensuing monologue. "Your visa is approved for a four-week residency. Accommodations for your use have been reserved at the Golden Lotus, Level Four, Tunnel Twenty-One, Bays Seven through Eighteen. Please regard this as your home away from ... Austin, Texas.

"An account with credit in the amount of forty thousand Neumarks has been established in your name with Marsbank Pty. Limited. Statements will be sent on a six-month delay at the then-current exchange rate to your home bank... the Double Eagle Bank N.A. of Austin.

"While your tourist visa includes no travel restrictions among Mars s various complexes, please be aware that many communities enforce multicultural sensitivity awareness. Also, you may not engage in any form of employment for either salary or wages, actual or deferred, while you are a registered guest of Mars.

"Mars quarantine laws require you submit to examination by a registered medical practitioner to ensure against the spread of communicable diseases. An appointment for this purpose has been made in your name with Dr. Wally Shin, Level Two, Tunnel Nine, Bay Six, at fourteen hundred hours today. Please be prompt and do limit your contact with others until after this examination.

"Thank you and have a good day," the voice concluded.

"Excuse me, but—"

The screen flashed its original message, in six languages.

Demeter checked her chrono. "Hey, Sugar! What's local time?"

"Thirteen hours, forty-seven minutes, Dem."

"Yikes. I'm going to be late to this Dr. Shin's!"

Coghlan gathered her two bags and headed down to the end of the corridor—the only end that seemed to make connection with the rest of the complex. She hoped to find, real soon, some tunnel numbers and maybe a static wall map with a big you-are-here sticker. Going back and asking directions of the computer grid sounded like a jackass idea, and Sugar's inertial compass was getting too easily turned around in this maze.

Demeter had made about seven left turns, all the time moving into wider and more crowded corridors as she went. Around her the air was filled with the treble whistlings of people in casual conversation.

Most of the tunnels in the Tharsis Montes complex were raw rock cut in smoothly arched tubes between tiny, hexagonal chambers. Side entrances from these little foyers led into the residential or commercial suites that made up the community. The rock surface, gray with red and sometimes black streaks, was sealed off inside with clear epoxy. The residents could never forget they were living underground—and under strange ground, too—instead of wandering through sterile internal corridors of white or beige tile.

As Demeter passed from one hexcube to the next, someone came up fast behind her and caught at her elbow.

"Excuse me, ma'am?"

She turned. A young man, curly brown hair and an Oriental cast to his eyes, was wearing a determined frown. He didn't let go of her elbow. She noticed he had a blue armband stamped with citizen's militia in white letters, both in English and in some kanji characters.

"Yes?" Despite the rough handling, she tried to keep her voice level in John Law's presence.

He leaned in close to her ear and took a hearty sniff of her trademark perfume, Odalisque.

"Like it?" Demeter asked as coldly as possible.

"I'm going to have to cite you for a scent violation, ma'am. Mars's privacy code is very strict when it comes to infringing the sensory space of other citizens." He handed her a pink card with exposed gold contact pins across one end.

"What do I do with this?"

"You redeem it for the amount of the fine within five days' time. Any local terminal will handle the transaction for you."

"And if I don't?"

"Then the card will emit an RF alert that locks you out of your place of residence, forfeits your transport rights, and forestalls any commercial transactions—such as food purchases—until you pay up."

"I see. And suppose I just throw the card away?"

"It's now keyed to your body temperature, ma'am.

The minute you discard it, the circuits will emit a siren that usually draws an immediate—and armed— response. . .. You'll notice the surface already has your fingerprints?"

Demeter looked at the citation more closely. Where her fingers had first touched it, her whorls were now outlined in purple and green. They didn't fade when she held the card by its edges.

"I suggest you pay the fine quickly," the militiaman said pleasantly. "Have a nice day . . . and, ma'am? Please wash off that stink as soon as you can."

Coghlan nodded blankly and hunted off down the corridor, clutching the card between the knuckles of the hand that held the shoulder straps from her bags. An arrow in the wall directed her to a broad ramp for Level 2. She walked down it, tripping occasionally in the weak gravity.

In a few more minutes Demeter found Tunnel 9 and Bay 6, but no Dr. Shin. There was a doctor's office on the right-hand side of the hexcube, but it belonged to a Dr. Wa. The scrolling light sign—in three languages, only one of which used the Roman alphabet—proclaimed: Dr. Wa Lixin, MD, PsyD, DDS ... Internist and General Practice for All Family Ailments ... Psychotherapy, Deep Regression, and Layered Syndrome Counseling ... Herbalist and Acupuncturist, Specializing in the Harmonious Wah. ...

Surely, that last word was a typo. "Way," Demeter corrected to herself.

Teeth Extracted While You Wait. The sign flickered and went through its loop again.

"And a humorist, too," Coghlan said. Well, if nothing else, this Dr. Wa could give her directions to the absent Dr. Shin. Probably a screwup in the physician's directory, or the Chamber of Commerce's referral service, or something.

Demeter pressed the button next to the door.

Dr. Wa Lixin was playing go against his desktop medical diagnostic computer—and winning. That bothered him because Dr. Lee, as everyone in the colony knew him, was simply a terrible strategist. So, when the grid let him win, he could only conclude it was buttering him up for something.

Everyone understood that the Autochthonous Grid—both the network here on Mars and the parent system back on Earth—was full of bugs and prone to error. Sometimes the cyber you were working on crashed its system through no traceable fault in the coding. Sometimes the system worked but your application crashed. Sometimes the application worked flawlessly but skewed your data with obvious—and unreproducible—results. Sometimes a Tenth Dan-level program dribbled away its stones in nonstrategic ataris and lost to a go-playing fool.

Some people said this was because the grid was infected with the mother of all viruses. If so, it was one so insidious that nobody had ever seen it, so rabbit-fast at replication that nobody had ever cornered it, and so mean that nobody would ever kill it. To actually kill the virus, they said, humankind everywhere in the Solar System that shared grid resources and datastreams— the wide nodes all over Earth, the local networks dug in on the Moon and Mars, the new nexus under Europan ice, and the freeloading terminals of the L-point colonies—every one of them would have to shut down their connected cybers simultaneously. Then they would all have to follow a prescribed set of debugging procedures and start up again using fresh-out-of-the-box system software and applications. Oh, and with all new data, preferably entered by hand from a penpoint or keyboard, or voice-op with a fresh sound-bit package.

And that just was not going to happen, folks.

Hard facts about what was actually wrong with the grid were difficult to come by, but Dr. Lee had heard plenty of rumors. The subject was the focus of a popular culture all its own.

One theory held that the grid was alive, that the virus infecting it was simple sentience. These people took it as an article of faith that a naturally occurring heuristic algorithm arose anytime you linked up a billion or so cyber units; each one acted like the node on a gigantic neural net. This argument made sense when you considered that most of those independent cybers were already operating in the teraflop range and could, with the proper programming, compose Elizabethan sonnets while beating any three geniuses at chess, checkers, and double acrostics. What the argument lacked was any scientifically verifiable underpinnings. Its adherents, however, had only to point to the grid itself and say, "Ecce logo!"

Some people maintained that the grid was God, pure and simple. This was the Gaea Principle written in silicon: any system that grew big enough and complex enough would begin casting random errors that looked like a sensible pattern. They said that God—or gods, or "the old ones," or some species of elves, sprites, or leprechauns—had once lived in rocks and trees, in the local babbling brook, or in a skin-covered ark somewhere. And now He or She or They lived in the sightlines and dwelt in the House of Number.

Still others said that the government had transmuted the grid as a means of spying on and controlling its citizens. In this scenario, every cyber malfunction or error was actually a fingerprint of the universal computing conspiracy The grid itself wasn't watching you and hexing your data; some faceless bureaucrat was at the other end of the fiberoptic, manipulating it for his or her own purposes. How this belief system squared with the fact that no single government, on Earth or anywhere else, was big enough to encompass the grid and all its multiplex activities, these conspiracy theorists did not bother to explain.

Yet another group insisted that the grid was actually the Devil, the Christians' fallen Lucifer, Archfiend and Destroyer. They insisted that many people—not they themselves, of course, but a "friend of a friend"—had already sold their souls to the machine. All you had to do, they said, was walk up to a common terminal connected anywhere into the grid and type in the command "MFSTO:". Then, depending on your identity and billing code, your background and status in society, and what the grid thought you had to offer, you might get an interesting response. The demon, popularly called "Mephisto," would propose to make a deal for something you wanted. Were you manifestly flunking a course at school? Mephisto could change your test scores and grade. Would you benefit from the futures price of kilowatt-hours or whole-kernel corn going up or down next September? Mephisto could arrange it. And what you had to give in return, that would depend . . . but it usually involved anything a human being could do or know or influence, and a machine could not. The Devil had a lot of resources, these believers said, because he controlled so very many willing hands and minds.

So, while everyone knew the grid was spooked, no two people could agree on just how it was done. They only knew that the problems were unpredictable, irreproducible, and bigger than any one human being and his or her personal concerns. The scale of error was probably also unimportant. Once the grid and its cybers had crunched your numbers, you tended to accept them. The data might have defects and shadings—but so what? The answers the grid gave were still a thousand times more reliable than if you took off your shoes and tried to do the long division on your toes. And, after all, the results just might be accurate. You paid your buck and you took your chance, the same as with anything else in life.

Dr. Wa Lixin placed a black stone 011 the nineteen-by-nineteen lattice dial the screen displayed. The computer responded by placing one of its white stones at random, then filling up the board with black stones and conceding the game with profuse compliments 011 Dr. Lees skill.

Then again, maybe the machine was just broken____

"You have a patient, Doctor," the screen announced. "Shall I open?"

"Go ahead," he said, turning toward the entrance to the waiting room. The door beyond, into the corridor, slid back on a plump young woman in a purple jumpsuit, her shoulders weighted down with luggage.

Dr. Lee perceived at once that she was more interesting to look at than the go board. She was high-breasted and narrow-waisted, with generous hips that promised good carriage and easy delivery. She had long, wavy brown hair, pulled back from her ears in a loose braid.

Her jade-green eyes were eerily clear and far-seeing; they looked like nothing so much as openings into another physical dimension. The coloring went well with her pale skin, which was dusted with the pigment splotches that the Caucasians dismissed as "freckles" and everyone else knew as a benign melanin irregularity. She was decidedly cute—if you liked Round Eyes.

"Yes? Can I help you?" he called.

"I'm looking for a Dr. Shin?" the woman said with a rising inflection. "The computer grid told me I had an appointment—"

"Are you Demeter Coghlan?"

"Yes, but—"

'Then I'm your assigned doctor, Wa Lixin. Everyone calls me Lee, though."

"Oh . . . Wah-Lee-Shin. I get it." She slid the bags off her shoulders onto the banquette beside the door and came through into the examination room. Her light hand still clutched something—a pink card, a fine from the local militia.

"You can put that down with your things," Dr. Lee said.

"But it'll go off, the patrolman said. And then the Marines or something—"

"Oh, piffle! They only mean to scare you, being a foreigner and all." He sniffed. "Odalisque? Nice scent, but a bit pervasive. We usually cut that brand here with three-eighths isopropyl alcohol. That'll get you past the gas sensors."

"Okay, thanks."

"Give me the card."

She hesitated. "What are you going to do?"

"I'll pay it out from my terminal. Then you don't have to worry about fending off the Marines."

"You'd do that for me?"

"And tack it onto your bill, of course." He checked the cards denomination. "It's only for ten Neumarks. Your money all comes from the same account, doesn't it?"

"Yeah, I guess. ... Say, do you really have that much surveillance here? I mean, just coming down from the fountain, I've seen swivel lenses, motion sensors, and earjacks in every corridor. Now you're telling me about gas sniffers, too. I didn't expect—"

"Expect what? Civilization? Modern technology?" Dr. Lee grinned. "Our grid gives us an interconnect level about equal to any medium-size Earth city. This isn't the frontier, you know. We don't have drunken cowboys and cattle rustlers—or whatever you were expecting."

"But I thought Mars would be a bit less... supervised."

"If you're looking for wide-open spaces, Miss Coghlan, go on to Europa. They're still chipping out the first public dome up there. But here on Mars we've got hot water already, plus a five-star hotel, a sushi bar— though I'd stay away from the fungus under glass—and a whole library of virtual-interactive entertainments. We even, sometimes, have the rule of law."

"I get you," she said with an answering grin. "I just thought maybe I'd for once gotten away from the more oppressive aspects of society."

"Not likely. Not with three thousand people crammed into less than twenty thousand cubic meters of holding pressure. That's only in Tharsis Montes, of course. Some of the outlying tunnel complexes are even more crowded.... So, are you here on business?"

"No, just playing the tourist."

"This is a long way to come for a vacation."

"It was an early graduation present from my grandfather."

"I see. Well, hop up on the table." Dr. Lee tapped the lightly padded surface.

The woman hesitated again. "Do you want me to take my clothes off?"

"My, you really do think we hunt buffaloes out here. No, just lie back and center your head, hands, and feet along the yellow lines." Dr. Lee helped adjust her arms. "This will only take a minute or two."

As she sank into the tables depressions, he reached into the lower cabinet and took out the transdermal air gun. He chafed her right forearm and then shot her with a full spectrum of telemites. While the diagnostic terminal probed her bones and soft tissues with ultrasonics, the beads would spread out in her bloodstream to examine her body chemistry, inventory her antibodies, and report on a dozen other organic functions. Each bead contained an array of technologies for medical analysis: gas chromatography and barometry, carbohydrate reagency, ion streaming, DNA combing—along with the telemetry to broadcast their findings back to the tables receptors. Each of these nanomachines was inscribed on a friable silicon wafer held together by a soluble substrate. Twenty-four hours after Dr. Lee had finished examining Miss Coghlan, her kidneys would sweep up and dispose of the shards of his most sophisticated diagnostic equipment, which he bought by the thousand from an off-planet catalog service.

"Ow!" she said, rubbing her arm.

"Too late." He grinned. "Now, just lie still for one more minute." He studied the terminal's screen as it built up the template display of a small female skeleton in three-dimensional outlines, coded beige. The bones enclosed various pulsing, squirming sacks—her organs and connective tissues—that were shown in standardized colors, mostly in the pastel range. The small gold ring on her third finger right hand, the silver bracelet with the communications charm on her left wrist, the metal snaps down the front of her garment— all came up as hard, white gleams on the screen, as would any other foreign objects or prostheses about or within her person.

"I don't see why you-all have to put me through this," Coghlan declared, her jaw and throat muscles blurring oil the screen as she spoke.

"You must hold still," he chided. Then Dr. Lee quickly brought his cursors up to the routine query points.

"But I've been in the equivalent of quarantine on that transport ship, for months and months," she said. "Surely any bug in my body would have died out by now."

"Of course," Wa Lixin agreed. "Still, we don't know what you might have picked up from the crew or other passengers, do we? Martian society cannot regulate interplanetary travel, you see, but we can prescribe for the citizens and casuals who actually touch down on our planet. So it's the law that everyone coming under our pressure be surveyed for communicable diseases, as well as for preexisting conditions that could create a liability situation." "Oh."

"Now, don't move!"

He rushed to complete the examination, taking the telemetered data and making his reference comparisons.

"You're clear," he said finally. "No abnormalities whatsoever. And quite healthy." Perhaps a little too healthy, considering the way she was stretching that jumpsuit.

"Hows that?" the woman asked, turning her head quickly, so that the upper part of the screen blurred again. "You got no traces of my accident?"

"Umm." It was Dr. Lee's turn to hesitate. "What exactly should I be looking for?"

"Well, 'head trauma' is the term they used back in Austin. You see, about a year ago I was having my hair done in an autocoif—that's an automated shampoo-curl-and-cut contraption?" she explained when he gave her a blank look. "Anyway, the machine kind of seized up. Seems the solenoids all burned out along one side of the helmet, or so the techs said later. It drove the point of the scissors right through the side of my head. Did it with such force that—"

Wa Lixin put up a restraining hand and stared hard at the scan on his screen. He zoomed and rotated the image to the approximate site of the injury she described. As he did so, curls and ridges of scar tissue—bone that had healed from an indented star fracture—built up around the outside of her skull. A smooth plastic insert gleamed whitely in the triangular hole that pierced her parietal plate just above the lower suture. The distorted tissue completed forming as he watched.

"Must be a lag in the processing," Dr. Lee murmured to himself. "All right, Miss Coghlan, I can see it now. Um ... do you have any recurring symptoms?"

"No, nothing serious. Just sometimes, off and on, I have trouble concentrating."

"Enough to bother you?"

"I cope," his patient said bravely—perhaps even defiantly. "Look, this has all been fun, but can I go now?"

"By all means. And welcome to Mars."

The woman nodded curtly, slid off the table, and moved quickly out into the waiting room. She gathered up her bags and approached the outer door, which opened for her automatically. Only then did she half-turn and give him a wave of farewell before stepping into the corridor. Then she was gone.

Dr. Lee tapped keys that stored her somatic image and biomedical history in the grids archives. That done, he settled in for another quick go game, before his next patient arrived.