After Ulla left for work at the start of each day, young Vepp, the orphan boarding with her, would sneak outside, leaving his T-puppet to teach math to an empty room. Vepp, clever Vepp, knew too much about math already. He could watch numbers cascading and arranging themselves in his head all day—better than buzzah. His math was not the sort needed in the factories. Vepp didn’t care about counting up and counting down. His numbers created a swirled world all their own.

Numbers were busy today, Vepp noted as he descended the rickety stairs to street level. Love and strife existed in his number-world as they did, Vepp supposed, in any real world—except that numbers didn’t suffer; numbers didn’t die. At this very moment—he refused to pay attention—the heroine of a buzzah drama was wearing his dead mother’s face. Ever since her murder—how many sleeps ago?—she’d been featured in his morning broadcast. Fortunately, Vepp could hold her true memory apart from buzzah. He cradled her inside his chest, inside a cry that only he could hear, a zero-source for all his numbers.

Walking downtown, clutching the collar of his coat against the cold, he observed the invariables: blue sun, white sky. The snowy wind was a variable; Lunagrad’s gray buildings were variables also. At this hour, the streets were deserted. Most workers were already at their posts, pulling levers, feeding furnaces. A distant clock-tower belled; the buzzah episode ended with a close-up of the heroine’s anguished features. To be continued, Vepp thought heavily.

On the plains, Umma would have been a witch-woman. She, like Vepp, had been a clever one, celebrating every number-story that he brought to her. But lately she’d begun to consort with those who styled themselves “thinkers” at the Aviary, a neighborhood pub; there, she must have said something, or done something, a little too clever.

Perhaps she’d propagated that rumor of a pregnancy. Some woman in the workers’ quarter had managed to get pregnant. Had Umma given birth to that rumor? Had Umma given birth? Vepp was old enough to know the facts of life. The conjunction of two numbers generated a new number. Thinking he might have been born that way, emerging from Umma’s body instead of an embryo-jar, Vepp shivered with an emotion he could not name.

Walking faster—he felt a pressure on his back, a probing, as of eyes espying his passage through the warrens—he reasoned that if he’d been born, born for the first time and not simply recycled like the rest of the crew, then he represented, impossibly, the endpoint of an infinite line. What was the word in Rush? Paradoks.

He was headed for the city center, where nothing ever changed. The buildings there were of a different design than the rest of Lunagrad—tall, elegant, they instilled a stillness in the air, so that citizens who walked among them tended to speak in low tones or even whispers. The blue-gray edifices had retained their stability since the time of Trespass, even as Lunagrad’s other buildings perpetually slid and tilted into bleak new block-forms. The buildings at city center were, however, inaccessible—no one lived or worked in them. Did this account for their stability?

Vepp, almost without thinking, dodged into an alley. He was being followed. He needed to take the least straight path downtown. He translated the numbers in his head into a grid of coordinates. The grid became a city map. Twelve, no, thirteen possible routes radiated from his present position. He paused, admiring the spillage of his numbers across a coordinate system. He especially loved the roots of negative numbers.

He lingered over that nonlinear alignment until a small sound—someone chuckling—snapped him out of his trance. There, at the end of the alley, stood a man. Or rather, stooped a man, an old man wrapped in a black robe. The man was wearing a wind-mask, an accoutrement once worn by nomads on the plains. Vepp, for one instant, imagined this man as the Straggler of legend, the last plainsman to finally find his way into the city. But no, the old man, his voice pitched high, addressed Vepp in modern city-speak: “Little snowflake, this alley’s a dead end. You’re wanted in the Aviary.”

The man turned away with a wave of his cane, commanding Vepp to come along. Vepp hesitated—he wanted to consult his numbers, but they, like a startled bird-flock, had flown to the far corners of his mind. All he had left were words, poor substitutes for thinking.

Vepp took a step forward. His words said Go! Hurry! But in which direction? Should he run home? After Umma’s murder, his real home had been foreclosed, the door nailed shut by the authorities. And now, on his nth day of mourning, an old man had appeared, wanting to lead him to the Aviary—the very place where his mother had committed her mysterious crime. Encouraged, perhaps, by the other criminals who loitered there. Would the same fate befall him?

Umma was a fearless one. His words carried a hint of reproof. Very well—he was fearless too. And he did, despite his reservations, want to meet his mother’s others. So, follow this man—and hope that he was actually going to the Aviary. Hastening into the street, Vepp slipped on a patch of ice and fell on his back. He heard the man, already several blocks away, laughing at him. A very quick and agile old man. Vepp got to his feet and ran to catch up, burning with indignation. Now something exponential was going to happen, he was going to yell, his yell would echo through the empty streets. But the old man had disappeared.

Just ahead, a police truck turned the corner, puffing steam. Vepp flattened himself into a doorway. Umma had always said, “You move like a monkey-spider, the way you slink and slither!” Young Vepp preferred to think of himself as a shadow, erring through a world of shining numbers. A null function…. The truck passed. Vepp couldn’t see the driver’s face, but thought he recognized the thug who sat atop the rear fender, rifle across his lap, lazily surveilling. That hard, scarred face was surely familiar. Another buzzah character?

Once the truck rolled out of sight, Vepp took his shadow door-to-door along the apartment block. Getting arrested belonged to the most uninteresting class of equations—those with only one solution. But Vepp was pleased to see his numbers return.

In the last doorway, the old man was waiting. Chuckling—maybe that was just his way of breathing—the man prodded Vepp with his cane, sun-colored eyes dancing merrily above his mask. “Who knows you, wants you,” he warbled in a bird-like voice. It was a phrase from a popular song, but Vepp inferred that he was speaking in code. Vepp could only shake his head, making a sign with his left hand that his mother had often made when frustrated with him. The man raised his eyebrows—he seemed surprised. “You show promise,” he piped.

The man turned and hurried away, black robes flapping. Vepp tried to keep up with him. “Who—” Vepp asked breathlessly, catching at the old man’s sleeve—“who are you?” No answer as the old man, quick-legged but bent of body—already devolving to an embryo?—continued ahead. They were coming to the Boundary, a zone between the warrens and downtown where the buildings, too twisted for habitation, seemed to be toppling, but with such slowness that two or three generations would pass before they finalized their fall.

From on high, a loudspeaker crackled as they passed. “Lunagrad!” it announced pointlessly in Rush. “Lunagrad!” The Boundary, for Vepp, was a haunted, hateful perimeter where murdered bodies were often deposited—where his mother’s body had been found. Nonetheless, for Vepp, the goal of reaching downtown, to bask in those serene and splendid spaces so conducive to mind-play, to number-play, overrode the perils of passage through this zone. He’d figured out a few routes where the Boundary was narrowest, where one dash would allow him to gain downtown in a flash. But—Vepp realized as he chased after the old man—they weren’t heading downtown. Instead, their destination seemed to lie somewhere within the Boundary itself.

“You—” Vepp panted as the old man skipped along, “you’re not taking me to the Aviary! There’s no pub here in the Boundary! There’s nothing, but”—he stammered, not wanting to say—“what’s d-dead, or dangerous!”

The old man stopped beside a tower that was tipping over, slower than time. He was not out of breath at all. His eyes glittered at Vepp. “We relocated,” he sang. “So much safer where it’s dangerous.”

Vepp spat into the snow. “Why should I follow you, starik? You’re not—” He faltered. His numbers rearranged their pattern. This was not some old codger, some starik he was facing, no, not at all. The spring in the step, the musical voice, the light in the eyes. Vepp, in one swift violent motion, pulled the hood off the masked figure’s head, to release a cascade of auburn hair. “You’re a girl!”

They stood there, nailed to that instant, motionless as the buildings falling all around them—while far away, a siren sounded. Vepp withdrew his hand. The girl’s eyes squinted angrily at him as she replaced her hood. There was a click, and Vepp looked down. A knife-point had emerged from the tip of her cane. She said, in a much deeper voice, almost muffled by her mask, “Don’t ever touch me again, sewer-bird.”

Another click, and the knife-point retracted. The girl hobbled away, at a less rapid pace. Vepp, despite his confusion, was compelled to go along. She was—who—was she? A number not equal to itself? Her gait was awkward but energetic; her body, beneath the heavy robes, seemed bent, misshapen. And why was she wearing that mask?

Again, the desire to shout rose in Vepp. A shout would clarify the problem, or reduce it to its lowest denominator. It was not in his nature to shout. Never before had he shouted, as he shouted now: “UMMA!” It came out wrong, as more of a cry than a shout. The name, without echo, hung strangely in the air.

No, erase that—he hadn’t shouted, he would never shout, his mother’s name least of all. He would keep his hurt wrapped in a respectful, righteous silence. He showed promise, after all. If he had shouted, the girl would have turned to reevaluate him, doubtless to dismiss or abandon him. He didn’t want that to happen. Vepp could see that the problem was not numerical but geometrical. He followed, a step or two behind, until they came to a building that had achieved its fall very long ago, to judge from the jumble it made on the ground.

Canted almost sideways in the middle of the pile was a dark red door. The girl tapped it with her cane. Hinges creaking, the door swung inward on a crazily crooked corridor. Vepp didn’t want to enter—but this entrance did entrance him. It looked like a logarithmic spiral. The girl made her little chuckle as she stepped inside. How sure-footedly she moved, a crooked girl in a crooked house!

Vepp crept after her, moving carefully. Once within, he saw that the walls gave off a dim blue luminosity, like flat angular versions of the sun. The lighting was no different than in any of the city’s interiors. But as they progressed into the fallen structure, Vepp found it increasingly difficult to distinguish up from down. Were they walking on the ceiling?

As they descended, or ascended, into the spiral, the girl reprised her song:

Who knows you, wants you—
Your name is like a chuckle on the run.
Who knows you, wants you—
Some day our luck’ll all be done.
You’re only one, but one leads to two,
So say to me, pray to me, spray to me, do!
Who knows you, wants you—

It occurred to Vepp that the girl had not been play-acting the role of an old man. Vepp simply had made a wrong assumption. As they wound their way into the spiral chamber, he wondered whether his entire view of the world was based on wrong assumptions. What, exactly, were the axioms of existence? Now everything and every person seemed equivalent to X the unknown.

How many turns had they taken? Vepp hoped that, if he needed to escape, he’d be able to find his way out again. It seemed as if they were walking through a random collection of architectural parts, a dwelling worse than a wilderness, where nothing added up. Vepp watched as the girl crouched and scrambled under a fallen roof beam—another demonstration of her agility. He attempted to copy her maneuver but hit his head on the beam. “Careful,” she admonished with musical laughter.

Now their way was blocked by a wide blue wall. The girl beckoned Vepp to come forward. Vepp did so, brushing dust off his coat. He saw that the girl was pointing with her cane to something in the corner. There, amid the rubble, rose a pedestal topped by a human head, sculpted out of Hurth’s hard earth—the bust of a “thinker.”

As they neared it, the bust activated: its eyes lit up, its mechanical jaw dropped. “Your name,” it croaked. The girl looked at Vepp, her eyebrows raised expectantly. Vepp, feeling a little foolish, made his formal reply to the bust: “Your name.” The girl also chimed in: “Your name.” Playfully, she asked the bust, “Do you like your new home, Kautsky? Isn’t this place much more—” she paused, looking at Vepp again—“philosophical than that old pub?”

The bust’s jaw moved up and down as it emitted a harsh sound—either a laugh or a lament. Both. The light faded from its eyes. The wall likewise lost its blue glow and—to Vepp’s wonderment—sank, clanking, into a slot in the floor. Beyond lay a dim cavernous space, expelling a pungent air of vod and pipesmoke.

“Dobraye ootro, comrades,” the girl called into the hall. “I bring you Umma’s son.”

Vepp heard a murmur of greeting from within. Warily he followed the girl into the space, his eyes adjusting to the gloom. At first, he saw only, at different heights, scattered points of light. Twinkling against blackness, the light-points reminded Vepp of something he’d seen before his birth—but how could that be? These were nothing more, he realized, than candle-flames. He was in a small auditorium with terraced seating. At all levels, men and women in workers’ garb lounged before tables set with candles and glistening glassware. These people, thought Vepp, have gathered here, in this derelict building, to start their day by drinking and smoking traumkraut—a rather dissolute company of “thinkers”! Doubtless they were criminals.

Yet Vepp was not afraid—he was not about to run away. For one thing, he wanted to solve the crooked equation that the girl presented. For another, this group of shady characters had been acquainted with his mother. What could they tell him about her death, her life? Behind him, the slab of wall went clanking, clunking, up again and locked back into place.

“Please be seated. You’re among friends.” A white-bearded man wearing a boilerman’s cap approached him, holding a bowl of flickering flame. He guided Vepp to a nearby table. Vepp looked for the girl, but she had moved off into the shadows. At that moment, the current buzzah broadcast, a variety show that he’d been suppressing, overwhelmed his mind’s eye with dancing figures. Quickly he translated those figures into a binary system of ones and zeros, and the scene quieted. He took his seat; the boilerman placed the fire bowl on the table in front of him.

Silence fell in the auditorium. All around him, the thinkers’ faces floated as if disembodied above their candle flames. What did they expect of him? Feeling the need to say something, he stammered lamely, to no one in particular, “N-never saw a door like that.”

“Pretty impressive, eh?” The boilerman seated himself on the opposite side of Vepp’s table. “The Red Engineers helped us build it, only a few sleeps ago.” He leaned forward over the fire bowl, endangering his beard. “They help us, from time to time. They make toy models of our systems of thought.”

At one of the upper tables, a voice spoke out: “Lunagrad itself may be just such a model. A toy of the god Roskosmos.”

“Does your thinking, then, proceed by analogy?” Vepp asked, surprising himself. He hadn’t meant to be so bold. Yet such ideas activated him, made his jaw move up and down. He too had employed analogy at a few key points in his play with numbers.

“We do invite the demon of analogy. But—” it was the boilerman speaking now—“there are other demons, demons of thought, demons of inevitable logic, who arrive uninvited. You must know this.” Vepp didn’t know whether that last phrase was a command or a concession.

“Umma—” Vepp spoke her name now, actually and deliberately—“Umma once told me of a demon named Chance, a demon who could move all the air to one side of a room, leaving the other side a vacuum.”

From the upper table: “The world will fall apart long before Chance gets around to producing such miracles.”

Another voice: “The world is beginning to fall apart already. We can and should expect miracles.”

Vepp tried again: “Umma—”

“—is dead,” the boilerman said with finality. “By order of the mayor Ob. No miracle there.”

Another voice: “Every moment is a miracle, the product of a random configuration, never to be repeated.”

Another voice: “Lvov, you keep repeating that same idea, over and over again. Have you no other thoughts?”

Another voice: “Thought and language depend on repetition. How else does a word preserve its meaning?”

“Stop!” Vepp was out of patience. All the pipesmoke, swirling up in demonic arrangements, was making him dizzy. “What do you want of me?”

“Son of Umma,” the boilerman intoned, “every question sets up its answer. What do you want of us?”

Another voice: “He wants to know what happened to his mother. He wants to know if we are to blame.”

Vepp, furiously: “I know that my mother was murdered by agents of Ob, in retribution for a—a crime—that she never would have committed, if she hadn’t joined your company!”

A pause, a tap-beep-tap, then a woman’s voice, faint, oddly buzzing: “Thinking is not encouraged in the ways and warrens of Lunagrad. The mayoralty sanctions the accumulation of knowledge by Readers and Red Engineers, but only if such knowledge works to Ob’s advantage. We thinkers, however, produce no value—we only disseminate doubt, partly by entertaining unauthorized suppositions. Yet who listens to us, apart from Ob himself?”

The boilerman leaned forward. “Do you recognize that voice, Vepp?” When Vepp, stunned, didn’t answer, the boilerman continued, “Another invention of the Red Engineers. They were tasked with repairing an instructional shrine damaged in a factory accident. Picking up the pieces, they found the voice-box, still issuing squawks and commands. They made a new box in exact imitation of the old one. And discovered that it could capture and repeat their own voices. Of course, they handed over their new toy, which they called a sound mirror, to Ob—but they also brought one, illicitly, to the Aviary for our use.”

Vepp: “You have no right to keep my mother’s voice imprisoned in that box!”

The boilerman: “It is not so much your mother’s voice as a mechanical pattern impressed with the memory of her voice. It is an apparition akin to buzzah.”

Vepp again heard the tap-beep-tap; then his own voice came sliding out of the shadows: “You have no right to keep my mother a prisoner—” The sound cut off.

“But—that’s different—that’s not what I said,” Vepp objected.

“Da, da.” The boilerman seemed embarrassed. “Even when we manage to glean some of Lunagrad’s secrets, we can never completely understand or control them. Complete control is an illusion pursued by Ob.”

Vepp pondered, for a long moment, the play of flames in the fire bowl. “What my mother said—about thinkers producing nothing of value—do you all believe that?” Part of his mind was busy breaking his mother’s statement down into several levels of statistical likelihood and nuance. He added, “Please don’t use the sound mirror to answer.”

Another voice: “Unlike the Red Engineers, we produce nothing of practical value. Our thoughts go where they will. They pass sometimes beyond human need, beyond Lunagrad.”

Vepp: “Back to the plains, then? Back to mythology?” He fingered a glass of vod that someone had placed in front of him. He’d never tasted vod.

Another voice: “Only if some proposition, an arousing thought, lures us there. Consider the myth, common to all tribes, of a Crash that spilled humanity across the face of Hurth. As a corollary to this myth, I advance the heresy that Lunagrad itself is the Crash site.”

Another voice: “You speak against reason, Pisarev. Was Trespass into Lunagrad a homecoming? Myth may go in circles, but history is a line. Humanity—so much is obvious—took shape on the plains. In Lunagrad, we are becoming something more, something other than human. Don’t you agree, Vepp?”

The boilerman (was he the host, the leader of this group?): “Beria, let us be cautious here. Agreement is the end of thinking.”

Vepp replaced the glass on the table, untasted. “When my numbers don’t agree, I know I’ve made an error. Everything seems in error here! You all led my mother into error.” He rose to his feet. “You caused her death!”

The boilerman, a big man with big hands, motioned Vepp to sit down. “Dear Vepp, error is the start of every story. Thought, in order to know itself, must take a wrong turn—turn inside out. It is a way of giving birth.”

“Tell me—was I born?” Vepp felt that the smoke was infiltrating his brain. “Or was I assigned to Umma by the mother-lottery? Did she collect me, in the usual way, from the Embryo Room?”

The boilerman: “Your mother was not put to death as punishment for birthing you.”

Blood, the voice of blood, roared in Vepp’s ears. So I was born—Umma gave birth to me. Not, in itself, an illegal act—but a highly unnatural one. Unheard of, in recent history. Vepp whispered, “Why, then, was she killed?” Dream-smoke filled the room, and he couldn’t help inhaling it. Was everybody in the room now whispering at once? Was this his answer? He heard a million reasons why, all divided by zero.

He saw the girl then, or a dream-version of the girl, standing nakedly near the doorway. Her flesh looked like a tan blanket decorated with tufts of hair, thrown carelessly over a skeletal scaffold. Her eyes peeked up at him from the floor. On the back of an adjacent chair, her robe hung like a second, discarded skin. All divided by zero.

“One thing is clear,” the boilerman was saying. He had removed his baggy cap to reveal a bald thinker’s pate. “Two things are cloudy.”

Another voice: “The world is a shattered version of One Great Thing.”

Umma’s voice: “Don’t listen to them, Vepp. Let them live in their cloud. You and I belong to the real story: the story of numbers. I was too loud in announcing that story, which, in all of Lunagrad, only you and I can comprehend. The thinkers don’t know it. Nor do the engineers. Not even the Readers—especially not the Readers. For here is where my inference led me, to the secret I revealed too soon: the Readers don’t understand what they read. They act as if they do—but what they understand is at most a feeling. In reading, they follow a sequence of formal relationships, the outlines of a number-story. The scroll-script has no content other than this.”

From the shadows, a chuckle. “Who knows you, wants you—” Vepp, dream-high, took a drink of vod. It burned his throat.

Umma’s voice: “Curiosity got the better of me. One morning the sirens went off, signaling a new Build. I went out, slipped through the police cordon to witness its growth. The Build’s surface was crawling with scroll-script, which I gazed upon at length. Since I am not a Reader, the script crazed my mind, of course. Ulla took care of you while I recovered. You wouldn’t remember this; you were so young.”

Vepp fought down the sob rising in his chest. “Umma—matushka—”

Umma’s voice, addressing him yet seemingly unaware of his presence: “The numbers—” was her voice somehow still alive within that box? Or was this a last testament she’d recorded for his benefit? “—numbers that compose the scroll-script are not as pure as the numbers in your head, Vepp. Your numbers enjoy free play. But the scrolls’ numbers are purposeful. They run along a track like train cars. They have a cargo to deliver. The Readers can pluck some of this cargo for Ob’s benefit. Most of it goes by them. But if you could read those numbers—if you could Read—”

“Reading is writing. To read the scroll-story is to write it.” A new voice, descending from a higher plane. Vepp shook his head. He wanted only to hear his mother’s voice now. But her voice had ended—someone must have shut off the sound mirror.

Cruel thinkers!—they continued their whispering, oblivious to his pain. He had lost his Umma. He had come here to find out why. And Umma herself had told him. And he had lost her again.

Vepp couldn’t listen anymore to the thinkers’ ongoing argument, all aerial diction and contradiction. He hung suspended in that black space studded with nails of light, a space vaster than Hurth. No words, no thought-waves could reach the limit of that space—

“Your mother was a thinker like no other.” This was a heavy voice, belonging to a woman who had not yet spoken. Vepp saw her face half-illuminated as she raised her candle in salute. Her blunt features identified her as a member of the Axis Axe tribe. “Umma told us that her numbers moved like characters in a buzzah show, always careening into new adventures. No T-puppet, no instructional shrine ever taught her how to tell a number story.”

Vepp said weakly, “She didn’t teach me—”

“She didn’t have to. Unlike words, numbers are inborn, coursing through your brain like vital fluid.” The woman closed her eyes, envisioning. “When humanity wandered the plains, so many generations ago, we saw how certain traits were passed from mother—mother and father—to offspring.” She opened her eyes again. “You are a throwback, and it remains to been seen how you will age.”

Vepp struggled to keep calm. This was a point not situated on any line. “Who—where—is my father, then?” Vepp had never known a father. He had never wanted a father.

No one answered. He looked around the auditorium—were there fewer candles? Cold air was seeping through the cracks of the fallen building. Two terms coincided for him now: truth, ruin. “Answer me!” he shouted.

The woman of Axis Axe: “Even on the plains, a father’s identity could remain mysterious, or be disputed.”

Another voice, and another: “Tell him. Tell him.”

The boilerman: “We believe your father was a man named Vunt. A neighborhood thug who went on to join the ranks of the police. Today he is Captain Vunt. Frequently seen riding on the back of a police truck.”

Vepp had spotted him, this very morning! But—his numbers realigned again—he’d also seen that man, several times, at the door of their apartment, trying to push his way in. Once Umma had hissed, “Quick, Vepp, the kitchen knife!” She’d always managed to chase the man away.

Another voice: “Umma once consorted with Vunt during Firedance. Back when she was about your age.” Vepp couldn’t imagine Umma, who’d possessed such a slow and serious demeanor, attending the frivolities of Firedance. “That thug Vunt harassed her ever after.”

The woman of Axis Axe: “As soon as she became pregnant with you, Umma began to be consumed by what she called her number story. She confided the story to her best friend Ulla, who, as agent of the underwork, introduced your mother to the Aviary.”

Vepp, his voice trembling, asked: “So the numbers derive from—from Vunt?”

Another voice: “Unlikely. We believe that, by chance, you received your numerical ability from the city itself. Vunt, through his blundering, provided merely the path for that signal.”

Another voice: “As a youth, Vunt once committed sacrilege by trying to break into one of the buildings downtown. Seeking treasure in the holiest of spaces—a bad idea!”

Another voice: “Those all-too-stable structures may in fact hold treasure. Perhaps—as Umma proposed—they function as the brain of Lunagrad, inciting new Builds, broadcasting buzzah.”

The boilerman: “In any case, as street legend has it, the brash young Vunt, after overleaping a fence marked ‘forbidden’, was caught in a maze of solid light. His accomplices watched as he was transfixed there, his feet off the ground, his mouth open. Eventually he wriggled free. He needed to be carried home. Once he regained consciousness, he refused to speak about what had happened.”

The woman of Axis Axe: “Soon after that, Vunt met your mother.”

Once more, a voice descending, as if from a higher plane: “Vepp is the product of writing.”

Someone laughed and said, “Ottor, you think of nothing but writing.”

Ottor: “Why not? Lunagrad itself engages in writing. Look at Vepp. He’s been inscribed with a new kind of story. A number story.”

“So, I’m a character,” Vepp said in a voice not his own, “created by the same city-mechanisms that produce buzzah.”

Ottor: “That’s not what makes you special. All of us are characters in the story of Lunagrad. You just happened to be injected with the city’s secret symbology, a language that was never supposed to be given to us. An inhuman language.”

Vepp: “An inhuman language… implies an inhuman mind.”

Around the auditorium, candles were winking out. Soon these workers, who so grandly styled themselves as “thinkers,” would have to report to their midday shift. But Vepp was not ready to leave. He raised his voice, his own voice now: “Comrades of Umma! Is a machine writing the story of Lunagrad?”

The boilerman, putting on his cap again: “My boy, you know the official doctrine. The god Roskosmos—the god common to all the tribes—first constructed the world, and finally this city as a world within a world, for the benefit of all humanity.”

Another voice: “Yet the god—which no myth pretends is a human god—stands apart from the world it has made. This world, once set in motion, requires no further divine intervention. The actions of the wind, the actions of Lunagrad are no more than traces left by the departed god.”

Ottor: “The myths of the plains no longer apply in Lunagrad. On the plains, everything—wind, snow, birds, stones—was a sign transmitted by the hidden god. We, the people, sang our stories and had no need of writing. Only after Trespass into the city did we receive the idea of writing as a set of dark scratches, writing as the visual counterpart of speech sounds.”

Vepp: “I don’t care about reading or writing. The numbers in my head come to me as a flow of relations that can’t be frozen into signs.”

Ottor: “But how can you show that flow to the rest of us? You told number stories to Umma. Those narratives, so precious to her, could have been saved by writing—allowing them to be performed without your presence. Reading is what melts the frozen signs.”

Vepp noticed that the crooked girl, once more covered by her mask and hooded garment, had quietly joined his table.

Ottor continued: “Since Trespass we have learned—Lunagrad has given us—signs for numbers, signs for words. The bare minimum needed for factory work. We can read these signs, manipulate them to some extent. But when we try to do more, to make our own meanings—” Ottor hesitated—“something happens. Right before our eyes, the signs twist and curl, becoming meaningless, a poor parody of the scroll-script.”

Vepp knew of this phenomenon. It was considered bad luck to write. Letter-symbols, if not directly related to practical needs, soon decayed into a series of blurs and smudges. To write appeared to be the sole perogative of Lunagrad, and beyond Lunagrad, the god Roskosmos.

The boilerman: “In the Aviary, we’re unable to write down our lines of argument. We even struggle to memorize them! Our most intricate disputations are soon trampled by the march of buzzah through our brains.”

In the background of Vepp’s awareness, the current broadcast, a variety show, continued to flicker; clowns performing pratfalls.

A man’s voice, speaking with the rough accent of the Hammer Hum tribe: “It was no better before Trespass. Living on the plains, our minds were afflicted with mythical thinking. In the city, we are burdened with buzzah.”

A bitter voice: “Lightened, not burdened! Workers love buzzah as a respite and a refuge from toil.”

Vepp, confessing: “My numbers enable me to ignore buzzah. If I look closely at a show, it turns into a pattern of ones and zeros.”

The boilerman: “Dear boy, you may be seeing into the very nature of the thing! But even on its surface, buzzah repeats a cycle of standardized stories. As a result, the workers laugh and cry, but never do they change their pattern of thought. The walls of the city are the walls of our minds.”

Ottor: “The arts that we brought from the plains—dance, music, storytelling—now languish in the city. Those in the underwork who believe that Lunagrad is guiding us toward some utopia are sadly mistaken!”

The man of Hammer Hum: “Another, more militant, faction of the underwork seeks to shut down buzzah. These different factions are united only in their desire to depose the mayor.”

The boilerman: “We hope there are none of Ob’s spies among us here today.” He was about to say more when a screech resounded through the auditorium. Everyone stood up. The door was descending into the floor again. Vepp half expected to see Vunt waiting outside to arrest him. But there was no one there. Smoke streamed toward the exit like thoughts escaping from a dying brain.

Ottor cried out: “One day, I will journey beyond the city to write! Upon the bare ground of Hurth, I will write my philosophical poem, The Avian Revelations! Out there, on the plains, my words will not be erased!”

The man of Hammer Hum: “Out on the plains, you’ll have nothing to eat, and no one, except yourself, to read your poem. Finally, the wind, the hand of Roskosmos, will erase your poem.”

The thinkers prepared to depart for their midday work shift. The boilerman approached Vepp. He was holding a box—the sound mirror. “We want you to have this.”

Vepp, feeling he was being duped somehow, took it from him. The metallic box, about the size of his hand, was lighter than he expected. One of its sides was indented by a vent-like opening. Vepp asked, “How is it activated?”

“It is self-activating—you will see.” As the thinkers shuffled toward the door, some murmuring “your name” to Vepp as they passed, the bearded boilerman and the crooked girl remained standing at his table. Vepp held the box close to his chest.

“You know nothing but numbers,” the boilerman said after the room had emptied. “It is difficult for us thinkers to admit, but—maybe numbers are all that can be known, here in Lunagrad.”

The girl, eyes glittering above her mask, tapped her cane on the floor impatiently. The big man shrugged on his coat and headed for the exit. “Verra will tell you the rest.”

Her name was Verra. Turning toward her, Vepp, quite suspicious now, inquired: “The rest?”

“The rest,” she trilled, “is all your numbers. You must bring them to the Readers.”

Vepp blinked, uncomprehending. “I came here on account of my mother. I found out what I needed to know. Of my birth, and her death. The Readers mean nothing to me. Leave me in peace.” Gently he set the sound-box on the table, rubbed his face, started to put on his coat.

The girl whacked her cane against the tabletop, just missing the sound-box. “Sewer bird,” she hissed. “If you learned anything here, it’s thanks to me. I brought you here.”

Vepp wanted to run away through the open door. But he knew the girl was quick, she could easily cut him off, even strike him with her cane. Picking up the sound-box, he backed away. “What do you want of me?”

“There is more to be learned. Your mother, endowed with your numbers, discovered the true nature of the scroll-script. The Readers understand only a fraction of that content. You alone can tell us the rest.” She danced toward Vepp slowly, her steps mincing, menacing.

“R-reading is the way to madness,” Vepp stammered in fear. “They said my mother went mad when she tried to read.”

“So she did, for a time. She had no goggles to protect her, no Reader to guide her.” With an accurate lunge, Verra poked Vepp in the chest with her cane. “You will be wearing goggles, with a Reader to guide you.”

“There are no more Readers.” Vepp, in his anguish, felt the numbers running away without him. Take me with you, O irreducible ratio! “Ulla told me the other day. Mek is dead, poured back into his embryo-jar. And Blenk, his disciple, has gone into hiding.”

Verra chuckled. “Mal’chik, I am going to bring you to Blenk, to his hiding place, in a bad neighborhood near the new Build. Together you will Read the latest scroll-script, and tease out Lunagrad’s secret number-story.”

“And my head will be shattered in the process! I am no Reader. You’re asking me to go on a suicide mission.” Vepp, clutching the sound-box, turned his back on the girl. What am I to do?

The box answered, chirping “Read, Vepp.” In Umma’s mechanical voice. “Vepp, read.” Vepp sank to his knees, sobbing. A certain ratio filled his soul, pouring all his numbers nightward.

* * *

Under the pale blue sun, they picked their way through the rubble of the Boundary, amid buildings that were simultaneously standing and falling. The air was biting cold. They were going back to the inhabited neighborhoods.

“Oh, the darkness of your day,” Verra sang, either to Vepp or to Lunagrad. “Oh, the starkness of your stray—”

Vepp followed her, stumbling, holding the sound box tightly against his chest. He hadn’t said a word since leaving the Aviary. The box itself was now emitting little peeps, as if a bird was trapped inside.

The sun offered no comfort from the cold. The sun uses its light only to make shadows, Vepp thought. He stumbled again. Nothing added up. Up or down.

Verra ceased her singing. She had stopped—not to wait for him, but to look at something moving just ahead.

People: two older boys, stepping out of the shadows. They were shaven-headed, wearing street-gang rags. Carrying spiked clubs.

“Hey, podrooga,” they called, approaching. “Did you find something? Hey cripple, what’s your friend got there, a treasure box?”

Verra glanced back at Vepp. “Stay behind me,” she whispered. Vepp was still dazed by his experience in the Aviary. But now an icy sensation crawled through his bowels. He couldn’t move, couldn’t breathe. He heard a click as the blade emerged from the tip of Verra’s cane.

Vepp knew that criminals were supposed to lurk in the Boundary—yet, on none of his expeditions downtown, sneaking from shadow to shadow, had he ever encountered any. Had these two been tipped off somehow?

The larger boy advanced on Verra, swinging his club casually. “Give us the box, and you go unharmed,” he said. The smaller boy circled to the right, holding his club upright, as if it was a prayer-pole. Vepp saw their strategy. While Verra confronted the larger boy, Vepp stood exposed to attack by the smaller one.

The sound mirror had fallen silent. Boy One flicked his eyes to the left, a signal to Boy Two. They began to close in.

With impossible alacrity, Verra sprang at the larger boy, impaling his throat with her blade. He fell backward, gurgling, spouting blood. Both Vepp and the smaller boy yelled in dismay. The smaller boy took a step toward his fallen accomplice, another step toward Vepp. The look on his face was wildly uncertain.

Verra turned to face him, chuckling, her movements fluid as black poison. “Amateurs,” she spat. She pirouetted, dancing toward the smaller boy, who, with a gasp, turned and ran for his life. He soon disappeared among the twisted buildings. The larger boy lay dead in the snow, blue sunlight purpling the pool of blood around his head.

Vepp had just witnessed a murder. Verra did it to protect me, he thought. Nonetheless, he was shocked to his core.

Verra retracted her blade, waved at Vepp. “Let’s keep going,” she commanded. They skirted around the body. Wasn’t it wrong to just leave him there? Vepp wondered as they continued in silence, steps crunching in the snow.

They needed to go noonward, toward the workers’ quarters. As they went, Vepp kept peering over his shoulder, half expecting the dead boy to rise again. But the boy lay still, his blood steaming in the cold. There was a great and growing weight on Vepp’s soul, making it difficult to walk, to talk.

Finally he stopped. Verra noticed, looking back at him with a raised eyebrow. Finding his voice, Vepp asked, “Who are you? What are you?”

In singsong, the crooked girl answered, “What is the veracity of error? I am Verra.” She turned and hobbled away. Vepp had no choice but to follow, clutching the box with his mother’s voice inside.