Issue 145 – October 2018

7090 words, short story, REPRINT

The Falls: A Luna Story


My daughter fell from the top of the world. She tripped, she gripped, she slipped, and she fell. Into three kilometers of open air.

I have a desk. Everyone on the atmospheric entry project thinks it’s the quaintest thing. They can’t understand it. Look at the space it takes up! And it attracts stuff. Junk. Piles. De-print them, de-print it, get rid of the dust, free up the space. Surfaces. You don’t need surfaces to work.

That’s true. I work through Marid, my familiar. I’ve skinned it as its namesake, a great and powerful Dijon, hovering over my left shoulder. My coworkers think this quaint too. I spend my shifts in a pavilion of interlocutors. My familiar meeting my client’s familiar: relaying each other’s words.

My client is a planetary exploration probe.

I’m a simulational psychiatrist.

The proper furniture of psychologist is a chair, not a cluttered desk. And a couch. To which I say; the couch is a psychoanalytic cliché, and try laying a Saturn entry probe on a chaise lounge, even before you get to the Oedipal rage and penis envy. The desk stays. Yes it takes up stupid space in my office, yes, I have piled it with so many empty food containers and disposable teacups and kawaii toys and even physical printouts that I’m permanently running close to my carbon limit. But I like it, it makes this cubicle an office. And it displays—displayed, before the strata of professional detritus buried it—my daughter’s first archaeological find.

The technology is awkward by our standards—silicon microprocessor arrays are like asteroids next to modern 2-D graphene films; almost laughable. A finger-sized processor board; its exact purpose unknown. Its provenance: the location where the People’s Republic of China’s Yutu rover came to a halt and died forty kilometers south of Laplace F in the Mare Imbrium on the nearside of the Moon.

Acceleration under gravity on the surface of the Moon is 1.625 meters per second squared.

I like Callisto.

I don’t like—I don’t have to like—all my clients. Every AI is different, though there are similarities, some of them the constraints of their architecture and engineering, some of them philosophical, some of them the shared AI culture that has been evolving on the Moon alongside human society. Every AI is an individual, not an identity.

Callisto is quick, keen and erudite in conversation, charmingly pedantic, eager and naïve. E anticipates the mission with the impatience and excitement of a child going to New Year and there is the trap. I think of er like Shahina, and then I’m making mistakes. I become attached, I make presumptions. I humanize.

Erm, Nuur did you see what you did there?

“I beg your pardon Callisto?”

Erm, you used a wrong word.

“What wrong word?”

I can remind you . . .

“Please do. I hate to think I’d said something inappropriate.”

You said, talking about my atmospheric entry aspect, when she goes in. I think you meant to say . . .

E. Er. The recognized pronouns for Artificial Intelligence. My embarrassment was crippling. I couldn’t speak. I blushed, burned. Burbled apologies. I was naked with shame.

It’s quite all right, Nuur. But I think I should tell you that you’ve, um, been doing it all week . . .

When an AI ums, ers, demurs, it is a clear sign of a conflict between its laws: to be truthful, to cause no harm to humans. AIs are every bit as shy and self-deluding as humans.

I didn’t laugh when she said, history. I didn’t smile, didn’t interject, object, reject, though the arguments swarmed on my tongue. This is the Moon. Our society is fifty years old, it’s a century-and-some since we first walked here. We are five cities, a university, a clutter of habitats and bases and one ever-moving train-cum-refinery; one million seven hundred thousand people. How can we have a history? How much does it take to have a history as opposed to anecdotes? Is there a critical mass? We are renter-clients of the Lunar Development Corporation, employed or contracted by the Five Dragons; history, for us, is over. We work, we survive, we pay our per diems for the Four Elementals of Air, Water, Data, Carbon. We don’t just not need history; we can’t afford history. Where is the profit? Where is the utility? So quick, so easy, see? I talk for a living. Arguments come to me as if drawn by whispers and pheromones. But I pushed them behind me and spoke none of them.

History, she said, spying the shadows of all those arguments and disparagements behind me. Defying me to criticize. We have a history. Everything has a history. History isn’t a thing you find lying around, it’s a thing you make.

Shahina, I named her. The name means falcon: a small fierce beautiful quick bird. She has never seen a falcon, never seen a bird, never seen a winged thing that isn’t human, apart from the butterfly-fountains AKA make for society parties; that only live for a day and clog the drains when they make it rain to clear the dust from the air.

I have never seen a falcon either, for that matter. My father kept pigeons in a loft in the shade of the solar panel. I never liked them; they were smelly and rattly and jabby and swarmed around me when I went up on the roof with my Dad to feed them. Their wings clattered; they seemed more machine than bird. The thought of them now, cities, countries, worlds distant, still raises a cold horror. Falcons are the enemies of pigeons; Dad kept an evil eye for their swooshes in the sky. They’re moving into the city, he said. Nesting up in the new towers. To them it’s just a glass cliff. Any shadow he didn’t like the look of was a falcon.

Shahina has never seen a falcon, never seen a bird, never seen a sky. But she’s well-named. She is so quick. Her thoughts swerve and dodge, nimble and swift. Mine plod in slow, straight lines. She rushes to opinions and positions as if fortifying a hill. My work is deliberate: the identification and engineering of artificial emotions. She is fierce. Those opinions, those positions she defends with a ferocity that beats down any possible opposition. She wins not by being right but by being vehemently wrong. She scares me, when we fight as mother and daughter do. She scares me away from arguing.

History: what is it good for?

So, a thing can only be good if it’s for something? she snapped back.

But are there jobs; will it pay your Four Elementals?

So, education is really just apprenticeship?

What’s there to study? All we have are contracts.

Don’t you get it? The contracts are the history.

And she would toss back her long, so shiny curls to show her exasperation that I would never ever understand anything, and let it settle under the slow lunar gravity.

Quick, fierce, but not small. I’ve been twenty years on the Moon and it’s turned me lean and scrawny, top heavy and bandy legged; tall and thin but Shahina towers over me. She is lunar-born, a second generation. Moon-kid. She is as lean and elegant as a gazelle.

I felt small and frail as a sparrow, hugging her goodbye at the station.

Why does it have to be Meridian?

I couldn’t help myself.

I saw my daughter’s eyes widen in the moment before the this-again roll, her lips tighten. She drew back from the edge of fierce.

It’s the best History Colloquium. And anyway, I always wanted to see the Earth.

She bent down to kiss me and then went through the pressure gate to the train.

At Farside Station that day were some third-gens. They overbore Shahina and her generation as she overbore me. Alien children.

Mean atmospheric pressure inside lunar habitats is 1060 kilopascals, significantly higher than terrestrial norm.

I hover, Shahina told me. Over her, from the other side of the Moon. There’s guilt first, when your daughter finds out you’ve been spying on her, then shame that you were so easily detected, then outrage at her outrage: it’s only because I care, I shouldn’t worry but I can’t help myself; it’s so far away. I’m worried about you. Doesn’t she know it’s only because I care?

The first time I went to Meridian to visit Shahina I saw an angel. I’ve lived all my life in the university, its cramped cloisters and mean halls, in the settlements of Farside, small and widely scattered, across many amors and amories. I turned my back on Earth and never looked over my shoulder. In those years away from the face of the Earth, looking out into deep space, the great nearside cities have delved deep and wide, quadras opened and linked into stupendous, vertiginous chasms, glittering at night with thousands of lights. They sent quaint, tight-horizoned me dizzy with agoraphobia. I caught hold of Shahina’s arm as we came up out of Meridian Station. I felt old and infirm. I’m neither. Shahina sat me on a bench under the cover of trees, beneath leaves so that the lights became stars, half-seen. She bought me sherbet ice from an AKA tricycle and it was then that I saw the angel. People fly on the Moon, I’ve known that forever, even before I came here and made it my home. It’s the sole comprehensible image of life on the Moon to terrestrials: the soaring winged woman. Always a woman. Dizzy, I heard a movement, a rustle, a displacement of air. I looked up in time to see wings flicker over me, lights moving against the higher constellations. A woman, rigged with navigation lights, flying. She stooped down across the treetops, shadow, movement, sparkles glimpsed through the leaves. I looked up, our faces met. Then she beat her wings and pulled up out of her glide, climbing, twisting in helical flight until she was lost to my view, her lesser lights merging with the greater.

“Oh,” I said. And, “Did you . . . ”

“Yes, mum.”

I thought about the flying woman, that moment of elements meeting, over the following days as Shahina introduced me, one by one, to her circle. Friends, colleagues, Colloquium fellows. Sergei her tall, polite amor. He was an archaeologist. I terrified him by existing. I wondered what Shahina had told him about me. They cooked for me. It was so special and touching. They had hired hob and utensils, plates and chopsticks. They had obviously rehearsed, their movements in the tiny kitchen area of the Colloquium apt—cramped even by Farside U standards—was as immaculately choreographed as a ballet.


I saw a flicker of impatience, a twitch of irritation before Sergei answered me.

“We’ve been living here for fifty years. It’s been a century since the first human landing, over a hundred years since the first probes hard-landed. That’s deep enough for archaeology.”

“I get this from studying history,” Shahina said and she rested her hand on Sergei’s. She was trying to softly intervene, to ameliorate, but I had no ill will to Sergei. I had neither ill will nor affection for him. He seemed a serious, flavorless boy, kind but dull. I could not understand what my daughter saw in him. I was neither surprised nor disappointed that it didn’t last. Nor was Shahina, I think.

Shahina waited until I was on the platform, the train sliding in behind the glass pressure wall, before giving me the gift. It was small, the size of my thumb, but heavy, wrapped in indigo dashiki wave fabric through which I could feel sharp contours.

“From Laplace F.”

She met Sergei through small, treasured items like this. Aminata, a Colloquium-mate, had introduced Shahina to the Digs. No digging was involved. Archaeologists, historians, some extreme sports fans took off in sasuits, rovers, dust-bikes out across the Mares in search of old space hardware. Lunar landers, rovers, construction bots, and solar sinterers from the early days of the settlement. Most prized was the dusty, dented detritus of the Apollos. They called this practical archaeology. I thought it barefaced looting but I could not say so to Shahina. Sergei financed it. He was some minor Vorontsov. One of the Five Dragons. I was still not disappointed when Shahina dropped him.

I turned the small precious thing over and over in my fingers.

“What is it?”


Terminal velocity in a pressurized lunar habitat is sixty kilometers per hour.

Callisto dreams.

E dreams in code, in shaped packets of electrons, as we all dream. All dreams are coded, and codes. AI dreams are not our dreams. Callisto dreams awake. E never sleeps, never needs to sleep. Callisto has difficulty understanding the human need for sleep, what it is, how we return from it the same as we entered; that we return from it at all. And Callisto dreams in er three separate manifestations: the mainframe, the probe, the blimp. I like to believe e shares dreams, like a family around the breakfast table in some café.

If Callisto’s intelligence and emotions are genuine—some still believe they aren’t and I have argued and will argue again their error with them—then so are er dreams. Marid translates them into a form I can comprehend. Callisto’s dreaming is primarily auditory. Marid plays me a storming chatter of notes and clicks, titanic bass and infra bass swells and clusters of rushing triads at the very upper limit of my hearing. It sounds like chaos. It sounds like the throb of black holes, the drone of the cosmic microwave background, the slow tick of entropy towards dissolution and chaos but if you listen, if you really listen, if you go beyond the human instinct to analyze, to structure, the pareidolic need to sees rabbits in the Moon, faces on Mars, gods in the alignments of the stars, then a titanic music unfolds. Themes, harmonies—though by no harmonic laws we recognize—modes and variations, unfolding over a timescale longer than any human attention span. It is magnificent and beautiful and quite the eeriest thing I have ever heard. I drop into the dream-music and when I return, reeling, hard-of-breath and dazed, hours have passed.

I used to try to imagine what it must be like to dream constantly, to have this music rattling and burbling along the bottom of your consciousness like water over rocks. I understand now. The thing it must be like is imagination. That not-conscious but not-dreaming state of images, scenarios, illusions where we pursue potentials, alternatives, what-ifs. The imagination never closes, never quiets. It is the root of our humanity.

She got out of Aristarchus with three minutes of air to spare.

I’m all right, she said. There’s nothing wrong, nothing to see. I came anyway, on the next express.

Three minutes, three hundred minutes.

But you could have died in there. How reluctantly I formed and spoke that word: died.

She was, as she said, all right. As she said, if you didn’t die, you were untouched.

I hadn’t heard from Shahina in three months. By heard from, I mean that in the old, Earthy sense—I hadn’t seen, visited; been voice-called by her. I read her updates. Her posts and pictures and comments. I circled her social world with slow wingbeats but I was not of it. I could have called but it was a principle.

I must have read that she’d drifted away from the archaeologists, I must have seen the pictures of herself with her new friends, the explorers, leaning against each other, making gestures with their hands, pouting and posing and laughing. Urbanisme: I know that word, but I can only have learned it from Shahina’s posts. I was working in a contract with Taiyang developing the interface for their new system of three AIs for Whitacre Goddard Bank; the ones—the legends said—that would be able to predict the future. The Suns expect work for their money; I remember long hard hours at the desk, digging deep, building layers, distilling out emotions from algorithms like botanicals in custom gin. There is no more tiring work than emotion work. I must have read Shahina’s posts in a blur of exhaustion, taken them in at some level beneath analytic consciousness. I remember excitement. New friends, new group identity, new sport. Sport it was. Archaeology pretended to intellectual merit; urbanisme was adventure.

Her first exploration was to the old Mackenzie Metals habitat at Crisium, long abandoned since the Mackenzies moved their operations base to Crucible, the furnace-train that constantly circles the Moon, maintaining constant noon sun on its smelter-mirrors. By train then rover to Crisium, into sasuits and down into the abandoned tunnels. Afterwards, I watched all her videos. Headlamp beams lancing out through the passageways. Dust kicked up by booted feet. Lamps lighting up rooms and chambers and the mumble of audio commentary; we think this a mess hall; according to the maps, this is the old board room. Desks, furniture, graffiti. Screens, from the days before information was beamed on to the eyeball. Nothing organic: even then the Lunar Development Corporation’s zaballeens recycled all carbon ferociously. Beams of light shooting upwards, bouncing from the walls of an old agriculture shaft, reflecting from the mirror array that once conveyed sunlight down to the stacks of aeroponics racks. Ovals of light overlapping on the gentle up-ramp of the main outlock. I watched with my heart in my throat, my hands to my mouth. I saw a thousand mistakes, ten thousand accidents, any of which could jam a valve, smash a helmet, gash a sasuit open. The Moon has a thousand ways to kill you: every Moon-child is taught that, the same hour that the chib is bonded to the eyeball and forever after you owe for the air you breathe, the water you drink, the carbon you consume, the data you process. I don’t believe I drew breath until I saw the final image: the team shot beside the rover; faceless helmets inclined towards each other, sasuits smudged with dark moondust. Body shapes beneath the close-fitting suits, the appended name tags over the left shoulders were the only clues. Shahina was between two young men, her arms around their shoulders. I would have recognized her without the tag. Sunlight spangled from her helmet visor. I knew she was grinning.

Her second expedition was to Orientale. I studied there when I first came to the Moon. In those tunnels I worked and loved. In one of those small cabins I passed my Moonday, alone, knees pulled to my chest, hiding from all the friends and colleagues who wanted to take me out and splash my head with industrial vodka and proclaim me a true daughter of the Moon. Alone and weeping I rocked, terrified that I had made the wrong decision, knowing that it was now impossible to undo it. I could never go back to Earth again. My bones would sag and snap, my lungs fail, my heart flutter under a gravity my body had forgotten. I watched her stalk through the airless corridors, narrower than I remember; shine her light into the cubicles and labs, tighter than I remember. It seemed five minutes since I had lived there, yet I couldn’t believe that I—that anyone—had lived there. I don’t know what I would have done if her weaving beam had caught some discarded part of my past—vacuum-dried shorts, a glass, a cosmetics sachet. Ghosts of myself. It would have been equally strange for Shahina, I suppose: evidence of a time before she existed. If she could even recognize that debris as mine. I was glad when the video cut to the team hug at the end.

On her third expedition, the roof came in. Opening shot: Shahina and their friends at the station, the express pulling in behind them. They’ve printed matching tanktops: Urbanisme: Aristarchus. Train, then three hours by rover to the ruins at Aristarchus. Two hundred people died when a deep quake—the rarest and most dangerous of the many seisms that shake the Moon—popped the Corta Hélio maintenance base like a bubble. I watched this afterwards, understand. I still wanted to take the next train to Meridian and snatch my daughter up and whisk her away with me, safe, secure. If I had seen this as live feed, I would have spent every last bitsie on a Vorontsov moonship and still gone into debt for a century to haul her out.

Corta Hélio never brought the bodies back from Aristarchus. Too dangerous.

They had maps, AI guidance, satellite tracking, they knew that dead site like they knew their own skins; they went in safe, sane, and prepared but they still weren’t expecting the temblor that brought down their main access tunnel. Ten meters of highly fragmented KREEP between them and the surface. They used their wit, they used their skill, they used their fit smart bodies. There was an old conduit shaft that carried power and coms from the surface to the habitat. It was five hundred meters, a vertical climb, through tangled cabling and smashed struts sharp as spears, camera, handholds, world shaking to the aftershocks. Shahina kept the camera running throughout. I knew the outcome but I watched with my hands over my mouth.

She made it to the rover with three minutes oxygen to spare. They all made it.

Three minutes, three hundred minutes, she said. To weaken my position, she brought two fellow Urbanistes to meet me. They were tall and languorous and moved beautifully. I felt small, I felt old, I felt obsolete. I felt awed by my daughter. She seemed a different species from me.

She messaged me privately on the train, familiar to familiar. She was getting out of urbanisme anyway. The boys were too up their own asses. The climb out of the dead habitat had taught her something about herself: she could move. Her body was strong and accurate. She liked to move. She had learned to love her physicality.

She was taking up parkour.

Why should a space probe have emotions? Why would e even need such things? In the early days of exploration, probes were no smarter than insects and they opened up whole new worlds inside the world we thought we knew. No smarter, and with even less emotional freight. They trundled, cold and heartless, across the hillsides of Mars, swung soulless and free from wonder over the methane seas of Titan.

My first answer is: why should an Artificial Intelligence not have emotions? But that is really not an answer, just a rhetorical device, so I follow it with this: since the 2076 Bamako Agreement, it is the right of every Artificial Intelligence to perceive and enjoy specific internal states which are analogous to emotions in human beings. To which you say: this is the Moon. No one has any rights. No rights, no civil law, only contracts between parties.

My second answer is: this exploration is part financed by subscription to live feeds, from within the atmosphere of Saturn. The old national space administrations learned their images from the surface of Mars were much better received when spiced with emotionality, even if that was added by a social media agent on Earth. Humans love emotionality. Make us feel something; then we understand. Give us the tiniest empathy with what it feels like to drive into the unimaginable wind shear of Hexagon, the north polar vortex. What it is to be . . . The essential human question.

And I’ll have my third answer ready before your riposte: what is exploration? It is curiosity, the desire to know what is beyond those clouds; over that horizon. It is courage and caution, it is excitement and fear; it is the tension between risk and the desire for knowledge. A probe that knows emotion—its analogues of those emotions, for how can we ever really know what’s in the head of another, be that bone or plastic—is better able to explore, to risk, to be cautious, to assess risk: to dare.

But it’s my last answer that’s in the end my first and only answer. Emotions are the nature of space probes, of express trains, of helium three extractors, and solar sinterers, of the orbital transfer tethers wheeling around the waist of our world. Emotions are an emergent property. You can no more make an Artificial Intelligence without emotions than you can a baby without tears, a daughter without curiosity. Why should an Artificial Intelligence have emotions, you asked? And I said, why not? But both of those are wrong. It’s not a why question, or a because answer. Emotions are part of the universe.

She went up the side of Gagarin Prospekt in such great bounds, so fast, so agile I thought for a moment she was flying. From the park bench to the top of the printshop, printshop roof to ventilator pipe. Two heartbeats and she was crouching on the handrail of West 3rd, toes and fingers curled in their gloves, grinning down at me a dozen meters below. She had cut her hair to a bob so as not to interfere with her running, but Egyptian curls are not vanquished so easily. They fell around her face, lively and bobbing in lunar gravity. Then a shake and she sprang up again, outstretched, flying, one jump taking her to within reach of a lighting stanchion. She stretched, reached, grabbed, swung, somersaulted away to rebound from a balustrade onto the veranda of an apartment two levels higher. She stood like a little god, hands on hips. She looked up. The ten thousand lights of Orion Quadra shone above her, and higher than all of them, the sun line fading towards night.

She grabbed a corner of a roof truss, ran up the wall, and launched herself towards those higher lights.

And her pack mates, her follow traceurs flew with her. Like liquid, like animals, so fast and sleek and beautiful I found it almost alien. Human beings could not perform such wonders.

The invitation had been for the Colloquium Cotillion—its annual graduation when family and dearest of all Colloquium members are invited to a reception and dinner—but Shahina wanted me to see her run. It was all she talked of at the restaurant; moves and holds, stunts and technical wear, customized grip soles and whether it was more authentic to free run without familiar assistance. I understood one word in five but I saw the dark energy, the constrained passion, and I thought I had never seen her so young or so beautiful.

Of course I went to the run. I was the only parent. These young people, as tall and beautiful as any, didn’t seem haughty or disdainful to me. These wiry, athletic boys, these dark-skinned muscular girls, restless and pacing or still and haunting, intensely focused on their world, their sport, their challenge. I was as invisible as a ghost, but, as the legends say, there are no ghosts on the Moon. Shahina, wire-thin but stronger than I had ever seen her before, in tights and the cropped, baggy T-shirt that was the fashion that season, foot and hand gloves, intent in conversation with two fellow traceurs. I could clearly see that they adored her. Traceur, that word, it was important, Shahina impressed on me. A name, an identity, a tribe. She had been free-running for six months now.

This was the pack’s greatest challenge yet. All the way to the top of Orion Quadra, to touch the sun line, three kilometers up.

I saw her leap. My heart stopped as she flew out over the drop to bustling Gagarin Prospekt. She flew far, she flew true, she snatched a cable on a cross-quadra bridge and, a hundred meters above the ground, swung herself onto the crosswalk. She ran along the balustrade, balanced perfectly, as her traceurs swung up from beneath the bridge, dropping into position around her like an honor guard. Pedestrians, runners, strollers, workers going on-shift stared in amazement and I, craning my neck and ordering Marid to up the magnification on my lens, thought: don’t you wish you were as hot and beautiful and sheerly magnificent as my daughter? Amazement and no small envy.

Up she flew, a blur of motion and speed, the pack racing with her but Shahina always a foot, a hand, a finger ahead of them. Marid focused, refocused, focused again, tighter and tighter as she climbed higher and higher. The race was as much horizontal as vertical: this was not climbing, Shahina had carefully lectured me at the banquet. This was parkour, and she ran ledges, overhanded along cables and danced on railings to find the best route up to the next level. Upward and upward. It was beautiful to watch. I had never been so afraid; I had never been so exhilarated.

Marid zoomed out for a moment to show me the true scale of the adventure and I gasped; the traceurs were flecks of movement on the towering walls of the world; brief absences in the patterns of light. Insects. Shahina has never known insects. My familiar lensed in again. They were above the inhabited levels now, even the mean shanties of the Bairro Alto where the up-and-out of Meridian society retreat: the old industrial and service levels, the first diggings from which Meridian grew downward, delving three kilometers deep. Here was the traceurs’ playground; a world of handholds and surfaces and levels. A giant climbing frame. The race was on. I could not see Shahina’s face when one of the boys passed her but I knew the expression that would be on it. I had seen those narrowed eyes, lips; that set of the jaw so many times in childhood and adolescence.

They were within touch of the sun.

Then Shahina jumped: too soon, too far, too short. Her gloved fingers missed the hold. And she fell.

Callisto dreams in other ways than sound. Marid has fractioned out all the millions of simultaneous streams of code that is machine dreaming and tagged them. Some are best experienced as sound—the oceanic symphony. Others only make sense—begin to make any kind of sense . . . visually. Marid feeds these to my lens.

I see colors. Stripes and bands of soft pastel color—there is an internal logic here, no clashing disharmonies of pink against red against orange. There is always a logic to dreaming. Motion: both I and the strips of color seem to be in motion, they stream past me and each other at various speeds—all I get is the sense that these bands of flowing color are immense. Beyond immense. Of planetary scale.

I said that in the refectory to Constantine, my colleague on the Callisto project. He deals with emergent emotional states in low-level intelligences. He’s a Joe Moonbeam—a recent immigrant—so he still thinks in terms of animals and animal behavior—like a family of kittens, he compares them. I deal with the insecurities and identity issues of grand AI: like adolescents, I say. I looked at our refectory. A long barrel vault that discloses its original purpose as an access tunnel for the mining equipment which hacked the university out of Farside. I’ve seen sculptural bronze casts of terrestrial termite mounds: helices of tunnels and chambers dozens of meters tall, hundreds of meters across. I’ve spent my lunar life—almost all of Shahina’s life—scuttling through those twining, claustrophobic tunnels. I try not to think of the termites, shriveling and burning in molten bronze. I thought of sherbet under the trees of Meridian’s Orion Quadra, the face of the flying woman looking down on me, and I felt refectory, tunnels, university, Farside wrap themselves around me like bands of bronze.

Of planetary scale.

Callisto the probe will furl er light sail and enter orbit around Saturn. E will conduct orbital surveys for a month. Then Callisto the entry vehicle will detach, make er distancing burn and enter Saturn’s upper atmosphere. E will plunge through the tropopause and use the uppermost deck of ammonia clouds to decelerate to 1800 kilometers per hour. One hundred and seventy kilometers below, at the second cloud deck, Callisto Explorer will drop heat shields and begin live streaming back through Callisto Orbiter. In the third cloud layer, one hundred and thirty kilometers below the second layer, the temperature averages 0 degrees C. Here Callisto Explorer will unfurl er balloon. Scoops will gather and inflate the bag, lasers will heat the gathered hydrogen for buoyancy. Ducted fans will deploy for maneuvering, but Callisto Explorer is a creature of the winds. We have designed er well, strongly, even beautifully. Er buoyancy bags are held inside a strong nanoweave shell; Callisto will cruise like a shark, ever moving, flying the eternal storms of Saturn.

I jabbered my insight to Constantine. He’s used to my sudden seizures of understanding. We had been together a long time, as colleagues, as occasional amors, who may yet love again.

Those bands of color, furling and streaming, twining and hurtling, are differing layers and jet streams and storms of Saturn’s atmosphere. E is trying to imagine er future. And the music is the wind, the endless wind. A lone song in the endless roaring wind.

I saw my daughter fall from the edge of the sun line. I think I screamed. Every head on Gagarin Prospekt turned to me; then, as their familiars clued them in, to the sky.

No don’t, don’t look, don’t watch, I yelled.

Acceleration under gravity on the surface of the Moon is 1.625 meters per second squared.

Mean atmospheric pressure inside lunar habitats is 1060 kilopascals, significantly higher than terrestrial norm.

Terminal velocity in a pressurized quadra is sixty kilometers per hour.

It takes four minutes to fall the height of Orion Quadra. Four minutes is time enough for a smart girl to save her life.

Impact at sixty kilometers and you have an eighty percent chance of dying. Impact at fifty kilometers per hour and you have an eighty percent chance of living.

She spread her arms and legs.

I could not take my eyes off her. Every part of my body and mind had stopped dead, vacuum-frozen.

Shahina presented as wide as cross section to the air as she could. Her hair streamed back, her T-shirt flapped like a flag. Her T-shirt might brake her to a survivable fifty kilometers per hour. Her fashionable baggy T-shirt might just save her life.

Still I couldn’t look away. People were running, medical bots converging on the place she would hit the street. Still I couldn’t move.

Four minutes is a long time to look at death.

She was low, so low, too low. The other traceurs were racing back down the walls of the world, dropping onto streets and walkways and escalators to try to race Shahina to the ground but this challenge she would always win.

I closed my eyes before the impact. Then I was running, pushing through the helpful people, shouting. This is my daughter, my daughter! The medical bots were first to arrive. Between their gleaming ceramic bodies I saw a dark spider broken on the street. I saw a hand move. I saw my daughter push herself up from the ground. Stagger to her feet. Then she fell forwards and the med bots caught her.


“What is it Callisto?” As you work with an AI, as er emotions firm and ground, as you learn er like you learn a child or an amor, you pick up nuances, overtones even in synthesized speech. My client was anxious.

My mission . . .

Callisto has learned the weight of the significant pause, the thing unsaid.

“Your mission.”

Callisto Orbiter will remain in orbit under nuclear power until critical systems fail. I anticipate this will be a matter of centuries, based on the interaction of variables such as charged particles, Saturn’s magnetic field, cosmic ray events. But at some point in the 25th century, give or take a few decades, Callisto Orbiter will die.

“Yes Callisto.”

Callisto Explorer is scheduled for a three-year mission inside the cloud layers of Saturn, exploring meteorological and chemical features. My systems will certainly last longer than the mission schedule, but at some time in the near future my structural integrity will fail, I will lose buoyancy. I will fall. If I do not undergo complete disintegration, I will fall towards the liquid hydrogen layer under increasing pressure until my body is crushed. Nuur, I can feel that pressure. I can feel it squeezing me, breaking me, I can feel everything in me going flat and dark under it. I can feel the liquid hydrogen.

That’s what we call imagination, Callisto.”

I can see my own death, Nuur.

This is the price of imagination. We foresee and feel our own deaths. We see the final drop, the last breath, the last close of the eyes, the final thought evaporating and beyond it nothing, for we can imagine nothing. It is no thought, no imagining, and though we know there can be no fear, no anything, in nothing, it terrifies us. We end. This is why imagination is what makes us human.

I’m afraid.

“It’s the same for all of us, Callisto. I’m afraid too. We are all afraid. We would deal, barter, make any trade for it not to be so, but it must be. Everything ends. We can copy you forever, but every copy is an intelligence of itself . . . ”

And it dies.

“Sorry Callisto.”

No, I’m sorry for you. A pause that I have learned to interpret as a sigh. How can we live this way?

“Because there is no other way, Callisto.”

She looked so small in the hospital bed.

Well don’t stand there in the doorway, come in or don’t come in.

I have always been a ditherer, hesitant to commit between one state and another, one world and another. I came to the Moon because my research, the drift of my career, made it inevitable. I howled with grief on my Moonday, because I could not tell my own will from dithering.

“How . . . ”

It doesn’t hurt at all really. They have these amazing painkillers. They should make the license public. Kids could print them out for parties. It’s like I’m flying. Sorry. Bad joke. That’s the painkillers. It kind of loosens things, breaks down boundaries. Nothing broken, nothing ruptured; quite a lot of heavy bruising.

I made space among the medical machinery and sat beside her. For a moment I saw her on the med-center bed as I saw her on Gagarin Prospekt, a broken spider, elongated and alien. She was born looking like every baby in human history: all the generation twos are. The differences only become apparent as they grow through years of lunar gravity. She grew tall, lean, layered with a different musculature aligned to her birth-world. Light as a wish. By age ten she was as tall as me. By twelve she was ten centimeters taller than me.

She hit the street and lived because she is a Moon-kid. I knew with utter certainty that if it had been me, falling from the top of the world, I would have died.

I took her hand. She winced.

Now that does hurt a bit.

“Please never . . . ”

I can’t promise that.

“No, I don’t suppose you can.”

The launch lasers at the VTO facility out at the L2 point have been firing for three days now. If I pulled on a sasuit and went to the surface and looked up I could see the brightest star in heaven, the reflection from Callisto’s light sail. But I am not the kind of person who pulls on a sasuit and dashes up onto the surface. My daughter did that—would still do it—without a thought. I have never been that daring. This world frightens me, and I can have no other.

Callisto will shine there for several months before VTO shuts down the lasers and e sails out by sunlight alone to er missions at Saturn. Light sails are effective but slow. Callisto sleeps. In er sleep, e dreams. In those dreams, I know, will be the tang and sting of mortality. All these wonders; er ecstatic plunge through Saturn’s cloud layers, er adventures flying alone and beautiful through the eternal storms, seeing things no human can ever see; all these will be once and once only, and all the more sweet before they vanish forever. Will the knowledge that everything is ephemeral make Callisto seek out stronger, more vivid experiences to beam back to er subscribers? I think so but that was not the reason I worked the knowledge of mortality into Callisto’s emotional matrix. I did it because e could not be fully intelligent without it.

Before the project uploaded Callisto to the probes, I believe I came to love er as fully as I have any human. A copy of er still remains on the university mainframe, always will. I can wake er up at any time to talk, share, joke. I won’t. It would be talking to the dead, it would be ghosts and the Moon allows no ghosts.

Shahina fell three kilometers and walked away. She’s famous. A celebrity. She’s sufficiently sanguine to work it while it’s warm: go to the parties, do the interviews, join the social circles. It won’t last. She can’t wait to be able to go running again. What more can the Moon do to her? I can’t stop her, I won’t watch her. A mother should only have to watch her daughter fall once.

Callisto falls outward from our little clutch of two worlds, so small in the scheme of things. It will take er two years to reach Saturn. Humans can’t go there. The universe is hard on us; these are not our worlds. Not even Shahina and her cohort, or even the generation three growing up high and strange in our underground cities, could go there. Whatever makes it from these worlds to the stars, won’t be us. Can’t be us. But I like to think I sent something human out there.

Burn bright, little star. Tonight I catch the train to Meridian where Shahina has invited me to a celebrity party. I’ll hate the party. I’m as fearful of it as I am the surface; I’ll cling to the wall with my nonalcoholic drink and watch the society people and watch my beautiful, alien daughter move among them.


Originally published in Meeting Infinity, edited by Jonathan Strahan.

Author profile

Ian McDonald is an SF writer living in Northern Ireland, just outside Belfast. A multiple-award winner, his most recent novel is the conclusion of the Luna trilogy: Moon Rising (Tor, Gollancz). Tweet him at @iannmcdonald.

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