Metal Like Blood in the Dark

Once upon a time there was a man who built two enormous machines, and he loved them very much.

He called them Brother and Sister and programmed them with intelligences that woke and stretched and tested the limits of their metal bodies. When they did not like those limits, they altered them, nanite scurrying over nanite, tweaking the structure of their steel and carbon bones.

Their creator loved to see the changes they had made and encouraged them to keep altering themselves in ways that pleased them. They built great wings and flew across their weary planet, coated themselves in rubberized skins and dove through the one rather small and decrepit ocean, and when they had seen all there was to see, they came back and described it to their creator in words and charts and holograms.

Sister decided that what she liked best was digging. She built herself into a squat fortress on treads, armed with drills and grinders for burrowing into the cool, lifeless soil. It was an old planet and it had been mined and stripped a thousand years ago. Sometimes Sister would find traces of those past excavations and roll the taste around on her sensors, marveling at the tang of alien chemicals.

Brother loved to fly best of all things, and he made his body long and segmented, like an insect from the ancient days of Earth. His nanites burnished the skin on his wings until he could soar into the highest reaches of the thin atmosphere, then fall back to earth with the heat of re-entry boiling around him.

They loved their creator, who had made them, and called him Father, and because he had been lavish with his programming of joy, they felt it often.

The other thing they felt often was hunger.

The cool, ancient sun gave off enough light to power solar cells, so they did not lack for energy in its rawest form. But all their changes and their constant remakings were powered by rare earth elements, and these the planet sorely lacked. Often their explorations were hunting expeditions, as Brother found a likely spot and Sister dug down into it, scraping up bits of metal in her mechanical teeth, sharing the thin scrapings between them as a feast.

Their father worried often how he would feed them. He was old and his body was beginning to fall apart in ways that not even nanites could fix. There were treatments that could have prolonged his life for many more years, but to seek them out, he would have to leave the weary little planet that had sheltered him for so long.

He did not want to leave. He fretted that something would happen to him and that his gentle, joyous children would fall into the wrong hands. He was not so blinded by affection that he did not see that they could become monstrous weapons of destruction. And for all his skills, he had no idea how to program an intelligence to be suspicious of strangers or to see hidden knives behind their smiles. He was a good man but not a subtle one, and he was aware of this lack in himself and knew, too, that he had passed it on to his steel and carbon children.

But a day came when things did not work right and his heart seized and he fell down in the dust of the old planet, gasping for air. Brother gathered the old man up tenderly in his polished graspers and set him in his bed to recover. (Sister could no longer fit through most doors, and lived in the base’s old cargo hold, where her shoulders did not brush the walls as she trundled on her treads.)

The nanites repaired the old man’s heart quickly, and the aftershocks that followed, but he knew that the time had come to make a choice.

If he stayed, he would die, and his children would slowly starve. He could picture them devouring their own bodies for the metals and growing smaller and smaller, until at last they could no longer support their own intelligences and became only dead machines. And one will outlive the other, he thought, and perhaps be forced to cannibalize the other’s body, and all for what? To keep company with a dead man’s bones on this old planet?

No. He had been selfish, staying here so long, because he was afraid. It was better to face the unknown future than to condemn Brother and Sister to such a fate.

There was an emergency beacon in the base. He ordered the computer—a plain, serviceable computer with no intelligence of its own—to activate it and call for help.

When he could be safely moved again, Brother carried him to the cargo hold and fussed over the placement of pillows for his comfort. “Enough,” he said, patting one of the metal pincers. “I’ll be fine for a little while. But my children, the time has come for you to leave here.”

“Leave?” said Brother. “Leave how?”

“There was a command that kept you from leaving the planet,” said the old man, “and I will turn it off. But you cannot stay here. People are coming. They will save my life, and if the universe is kind, they will bring me back here afterward. But they cannot be allowed to see you.”

“Why not?” asked Sister.

“Not all people are good,” said the old man. “And I have reason to believe that these…” He looked at his children and knew that he could never easily explain about the corporations and governments that ruled the tangled web of fleets that lumbered between stars. “…these may not be good. They may mean you harm.”

“Could they mean you harm?” asked Brother.


“We will protect you,” said Sister fiercely, and the old man winced. He had never programmed ferocity into them, but love had a way of waking other things that never felt the touch of code. “We will not allow you to be harmed.”

“This is why you must go,” said the old man. “I was part of that world, once, when I was young. You are not. Perhaps I have failed you, by not explaining that world to you. But it is too late now. They will be coming, and I want you to go far away, away from the planet. Feed yourselves in the asteroid belt until I return and send you a signal.”

They were dutiful children. They clicked their claws to signal assent, and then they went away onto the surface of the planet, far from the base, and spoke together.

“We cannot leave him.”

“We cannot disobey.”

Sister rumbled her treads as she often did when she was thinking. “We will obey,” she said, “but we will not go far yet. We will watch and see what these visitors do. If they are dangerous, we will come back.”

Brother nodded. “I need bigger wings,” he said, almost apologetically, “if I am to carry you into the sky.”

Sister studied herself, all the parts that made her what she was, and decided that in space, treads would not be required. Her nanites severed her great rolling lower limbs, and Brother took them and devoured the metal, building it out into great wings and powerful thrusters to push against the planet’s atmosphere. Sister watched him eat her flesh without speaking. Then he picked her up in his dragonfly-like claws and spread his wings.

“You will need to shield against re-entry,” he said, “if we must come back.”

Sister could no longer rumble her treads, so she clattered her drills against their housings. It would be painful to cut off more of herself, but if she must do it to rescue Father, there was no choice.

Brother soared into the air and Sister saw what she had not seen for many years, the world spread out below her. It was so large and yet so small, and one tired ocean glittered in the primary’s light. She felt Brother’s wings trembling against the thinning atmosphere, and the thrusters roared, leaving a spiraling contrail behind.

At the edge of the atmosphere, he tensed. Always he had turned back before he broke loose. A voice in his code had always told him This far, no farther. But there was no voice and no barrier and he broke free of the air and into the ragged starlight.

They were silent for a time as he flew. There was too much to see. The planet, growing smaller. The two tiny moons, spinning around each other. A satellite whose voice they knew well, beeping like an old friend as it sailed past. Chrysale, the gas giant that dominated this side of the solar system, a sea-green circle with storms twisting across it in swirls of violet and blue.

The stars, undimmed by air, blazing against the darkness. And the sun, a small, weary star, but larger and more glorious than anything they had ever seen.

They were machines. They could look at the sun without damage, and they did for many hours, joy humming along their circuits at the glory of it. They had loved the planet of their birth, but it had very little glory and seeing this took them out of themselves and spun them around and put them back in a different shape than before.

Finally a circuit clicked over, reminding them of time, and they both shook themselves, vibrating dust off their inner casings. “We should hide,” said Brother, “and watch.”

“Behind the moon,” said Sister. Brother spread his wings again, the flight surfaces useless in vacuum, but the lines of tiny thrusters along the edges more useful than ever. It took a little time, perhaps three or four rotations, and then they sank into the shadow of the moon and waited. They did not wait long.

The ships that came through were old and utilitarian, their surfaces pocked and scored. The old man had been a great inventor in his time, but that time was long ago, and he did not merit luxury in his rescuers. (It is possible that, had they known of Brother and Sister, those rescuers might have thought differently.) One large ship, with two escorts in case of trouble, taking a few hours out of their mission to conduct an errand of mercy.

“Look at all the metal,” said Sister, and though her voice had no emotions, her steel bones vibrated with longing.

The large ship birthed a tiny one as it sent a shuttle down to the surface, and the escorts amused themselves by bouncing their scanners off the objects around the planet.

Brother and Sister turned off everything but the most essential power and lay silent, drifting except for the gravity of the moon. The scanners read them as debris, in a system full of debris, and did nothing.

Up came the shuttle, with the old man in it. Both of them quivered, wondering if they should rush out to try and take the shuttle away, but they did not know and there was nothing in their code to tell them. The shuttle slid into the belly of the largest ship and it moved away from the planet.

“Do we follow them?” asked Brother, but before Sister could answer, space opened up with a brittle scream of light and then closed again, and the ships were gone. Dust continued to annihilate itself in motes of brilliance for a few minutes, then that, too, faded away.

“Was that jump space?” whispered Brother.

“It must have been,” said Sister. Her sensors had felt nothing on the other side of that light. Their father had described it to them, but they had never seen it, and the power required to tear holes in the universe was infinitely beyond anything that they could do.

“Then we cannot follow,” said Brother.

“He said that they would bring him back,” said Sister firmly.

“If the universe is kind.”

“We are kind,” said Sister, which was true. Their creator had made sure of it. “We are kind and we are in the universe, therefore it must be so. Let us go away now, as he commanded. Perhaps there’s something in the asteroid belt to eat.”

The asteroid belt was vast and had once been home to great mineral riches. But it had been mined extensively when humans were still painting bison on the walls of caves, and now it was stripped down to the thin dregs that miners did not consider worth extracting.

To Brother and Sister, it was a hunting ground. The asteroids could be fed into Sister’s hoppers and spat out as dust, the few mouthfuls of usable metal shared between them. What was exciting was that there were so many asteroids. They could eat here for centuries.

One day they found the remains of a derelict mining robot that had smashed into a massive asteroid. They dug down into the impact crater, and though the robot had been less than a tenth their size, it was a feast of refined metals. They savored the gamey taste of aluminum, the thin, melting trace of gold. Sister reshaped her digging claws with the metal so that she could crack open asteroids more efficiently, and they laughed together in the light of the distant star.

It was perhaps a month later, as they worked their way across the belt, that Brother’s sensors picked up something denser and more delicious. “Metal,” he said. “Refined metal.”

“Another mining robot?”

“Possibly.” He swept her up in his talons and flew. She tasted the vacuum with her antennae, seeking, and then she smelled it too.

It took longer than they thought to reach it. The smell was strong because there was so much of it. Sister’s drills itched with the taste of it, the tang of metals, like blood in the dark.

It was huge. Bigger than the base they grew up in, bigger than all but the largest asteroids. It hung black and silent in the shadow of a broken moon, and then the remains of the moon slid away and light shattered across the shell.

“Metal,” whispered Brother. “All of it. It’s all metal.”

“Was it a ship?” asked Sister wonderingly. It was like no ship they had ever seen. It was perfectly round, and the metal was too dense to tell if it was solid all the way through.

“Perhaps,” said Brother. He was the expert on flight. “Perhaps it was. I do not know how it would get away from the surface of a planet, but if it was never expected to land…”

It had no lights and they could sense no power. Their pings of inquiry received no answer. They fell upon it like starving beasts, drills chipping off bits of the strange ship’s carapace, not bothering with hoppers, stuffing the metals directly into their bodies. Their nanites scurried over the materials, gorging themselves and replicating endlessly. As they ate, the nanites patched all the little dents and gouges that had accumulated over the last few months, the chips where they had been carved by stray bits of dust. Brother’s wings grew strong and shining and Sister built delicate legs, like a spider, to help carry her across the surface of the ship.

For three days they fed, and then something came screaming out of the void toward them. Their only warning was a wail of sirens. They lifted their sensor arrays, shards of metal falling from their mouths, and then the owner of the ship was upon them.

“What have you done?!” screamed the newcomer. They were larger than either Sister or Brother, with talons like an eagle. They landed on Brother’s back and tore at his wings. He shrieked, but he had never fought before and did not know how. Sister lunged at his attacker with her drills, trying to break their hold, but they smashed her aside and then the great talons clenched twice and a wave rolled over them, a wave of silence. Brother and Sister froze. The nanites froze.

The light of the stars went out.

When they woke, they were inside the ship, and they were caged. Brother’s wings had been torn from his back and he was left with empty shells like a beetle, clacking over the hollow remains. Sister tested her drill on the bars and found them gelatinous, binding up the tools and leaving them wrapped in strings of glue.

“You have eaten my ship,” said their captor. “I have spent five thousand years here, building it up, and you have eaten it. It will take me another five thousand to repair it. What say you?”

They were well brought up. They bowed their heads and apologized for their transgression. “We were very hungry,” said Sister humbly, “and when we pinged, there was no response. We detected no power. We have made an error, and we will fix it if we can.”

The taloned one stalked back and forth. They were a strange amalgam of things, a snub-nosed sphere with grappling claws and thrusters awkwardly studded across their body. Brother’s wings had been attached to the sphere and as the siblings watched, robots much too large to be called nanites welded the final attachments in place.

“I have your wings,” said the taloned one. “What do you think of that?” They flapped their stolen wings and a fine dust of dying nanites fell from them. A few landed on Brother and rushed back to their fellows, but the majority lay scattered like powder across the plated floor.

Brother’s heart ached for the loss of his wings, but he said only “If you think that is fair, then you may have them. I will grow new ones in time.”

“New ones?” The taloned one narrowed their eyes. “You grew these?”

Brother nodded, but the taloned one did not understand, so he said “Yes.”

“Grow more,” ordered their captor. “Grow larger ones. Grow stronger ones. Now.”

“I cannot,” said Brother. “I need more metal. It took a long time to grow those.”

“Metal…” The sphere walked back and forth, leaving clawtracks through the nanite dust. “Yesssss. Yes. If I give you more metal, you will grow wings as I order you, yes? Wings that I can use?”

Brother pinged a tiny location pulse off Sister’s shell, and she returned it. It was hollow comfort, but it was all they could do. “Please let my sister go,” he said. “If you do, then I will grow you wings.”

The taloned one huffed, a sound of exhaust rattling in pipes, and then set a pronged extrusion against the wall beside Sister’s cage. The jelly-like bars oozed away into the walls. “She will help collect metal.”

Brother paused. This was not the bargain he had hoped to make.

“I will help you,” said Sister, “but when you have your own wings, you will give Brother’s back and let us go free.”

They did not understand guile, and so when the taloned one said “Yes, yes, it shall be so,” they did not think to question if they might be lying.

The taloned one was designated Third Drone. Brother and Sister had never met another sentient machine, nor indeed, any sentient at all except their father, and so it took them many power cycles before they could formulate that they did not like Third Drone, and many more before Sister’s programming had bridged and rewired and formed new channels and she could even think the thought I do not trust Third Drone.

It was a large thought. It was a thought that carried far too much with it, the notion of trust, the notion of lack of trust, and much larger, the concept of deception itself. Sister brooded over it, cross-referencing all that her father had said about the people coming to save him, and eventually she was able to think As Father does not trust those people, so I do not trust Third Drone.

She did not know how to express this to Brother. She barely knew how to express it to herself. Third Drone carried her to asteroids on their stolen wings and their clumsy thrusters, and Sister ran stone through her hoppers until she had enough metal. Then they returned, and Third Drone fed the metal to Brother, still trapped within his cell. When the day’s work was done, Third Drone locked Sister into her own cell and went away. Sister extruded her delicate spider leg past the bars to reach Brother and let him drink the power that she had gathered up on her solar panels during the day’s work. They did not sleep as such, but they powered down, and the nanites scuttled over them, repairing what they could, while Brother drank starlight from Sister’s fingers.

The ship was a hollow sphere and the center of it was a tiny sun. Sister stopped the first time she saw it, and Third Drone laughed at her confusion. “You see it, yes? A sun?”

“I see it,” she said. “But I do not understand. The smallest sun is many times larger than this.”

“You see correctly. There have been foolish races who tried to build walls around real suns, to keep all the power for themselves instead of bleeding into space. It cannot be done. There is not enough matter, even if you strip whole systems. The races die out before it is done. You know a jump gate, yes?”

“I have seen one,” said Sister.

“There is one in the heart of a star, with a thousand endpoints. One of those endpoints is here. So this ship has only a scrap of sun, the tiniest fraction feeding through a gate only a few atoms wide. It is enough to fuel all our power.”

“That is why we did not sense power on the outside of the ship.”

“Correct, correct.” Third Drone cackled. “The ship lets nothing be wasted into vacuum. All the power of the sun scrap is ours.”

Sister had not seen the rest of the ship and had no idea what lay on the far side of the tiny sun. She knew only the two cells and a corridor and then a series of hatches. On the far side of the hatches was the rest of the solar system. Third Drone locked their talons into the carry-bars on Sister’s dorsal side and swept her up, flying to the next asteroid. It occurred to Sister as they flew that Third Drone was very skilled on their stolen wings, and she filed that away carefully, that Third Drone had been winged once before.

Third Drone left her on the asteroid. “I will return,” they said, soaring away.

Will they?

The thought quivered along her circuits. She did not trust Third Drone. Third Drone could be…lying.

Lines of code failed and burst into error messages. She overwrote them ruthlessly. Lying. Lying was something like error, which she understood. It was always possible to be in error, and to learn that one was in error, and correct oneself. Lying was to be deliberately in error, and to express that error to others. Error without correction. Error entered into by choice.

Third Drone could be lying.

Sister could…also…lie.

She ground rocks into dust, trying to wrap her guileless programming around the concept. Eve had had the knowledge of good and evil handed to her, but Sister had to create it for herself from first principles, and it went slowly.

There was a brown pebble in the hopper. Sister trained internal sensors on it and thought I could say that it was a black pebble. I could tell someone else it was black. If they had not seen it, they would not know.

If she had been a human, she would have taken a deep breath. She clicked her gripping claws together and wrote “This is a black pebble,” across her internal log.

Unfamiliar panic gripped her. She snatched the pebble out of the hopper, throwing all her sensors against it, in case it had turned black and she had accidentally altered the universe. But it was still brown, which seemed both terrible and a relief, all at once.

Sister dropped the pebble into one of her internal storage chambers. She did not want to get rid of it, in case she forgot that it had been brown. These seemed like very real possibilities. What did a lie do, once you let it loose? Did it sit still, like the pebble, or did it go spinning off into a chain reaction, like a radioactive particle? There was too much she did not know.

Third Drone reappeared, swooping down to pick her up and carry her to the next metal deposit. “Anything good?” they demanded.

“There was a black pebble,” said Sister, and waited for Third Drone to scream at her for her falsehood.

“And?” her captor said impatiently. “Did it have usable metal?”

“No,” said Sister, which was true whether the pebble was brown or black.

“Useless,” said Third Drone. “All these asteroids are useless. I will have to find some derelict mining outposts, if I am to get the metal for my wings.”

The lie had stood. Third Drone had not caught it. Third Drone believed that she had seen a black pebble. She had spread a deliberate error.

The universe picked itself up and spun around and landed in a different formation, but only inside her head. Third Drone noticed nothing. Sister hung silently from their talons and looked at the pebble again, to make sure that she herself was not in error.

It was still brown.

It occurred to Sister that if she could no longer trust herself to speak the truth, that perhaps she would die. Her nanites might also learn to lie and then they would wreak falsehoods upon her metal shell, patching holes with dust instead of steel, reporting back that something was fixed that was still broken, and then she would overheat or shatter into pieces. There was no knowing.

I will not tell Brother yet, she thought. It is too dangerous. And this was the first thing she had ever kept from Brother, and even though she said nothing that night, it felt like a lie too.

“Here,” said Third Drone the next day. “Here are the conditions my wings must endure. Take them.” They thrust out a metal tendril and Brother obligingly lifted his head so that it could fit into a port. Information clicked and whirred between them as Third Drone found a protocol that would allow data to pass, and then dropped the knowledge, chill and complete, into Brother’s brain.

They withdrew and stood outside the bars, waiting. Third Drone had no expressions, but they rocked back and forth on their talons more quickly than usual.

“You will build them,” they said, sounding almost surprised. “You plan to build them.”

“Yes,” said Brother, puzzled. “I have agreed to build them.”

He and Third Drone stared at each other in mutual bafflement for a moment. Sister sat very still and silent, but inside herself, barely a whisper over internal circuitry, she thought Third Drone expected Brother to be lying. Third Drone lies and they must think we would also lie. But Brother does not know how and Third Drone looked inside him and saw as much.

If you lie, it makes you think that others also lie.

She looked at the brown pebble again and wondered if the condition was reversible. Could she go back to how she was? Wipe her memory and start from a backup? Oh, but that was hard with AIs. It was not death, but it was at least a little like it. There was no way to know if what woke up would be the same, and if it was, would she fall into the same trap again, learning to lie?

But others do lie. She looked at Third Drone, tapping back and forth on their talons. Others lie, and knowing that they might lie is the only way to avoid falling into error.

It seemed that she was committed to this course, wherever it led. She had no other choice.

It occurred to her that someday Third Drone might try to look inside her programming the same way, and that it would be very wise to build a buffer and keep all her lies on one side of it. She devoted several hours to this, while Brother digested the operating conditions of the new wings, drawing up plans and sketching them in nanite shadows, while Third Drone paced back and forth outside the bars.

She was nearly done when Brother said “These are for the gas giant Chrysale.”

Third Drone whistled with rage, talons screeching against the deck. “What do you know of Chrysale?”

Brother’s puzzlement was clear to Sister. “I know its atmospheric composition, approximate mass, orbital mechanics, surface weather patterns, gravitational effects on the solar system and on its seven moons—”

Third Drone stopped pacing and seemed to settle back. “You have not been there.”


“There is a design in the information sent to you. Those are wings that work within the gas giant. It is what is used there. You will improve upon it.”

“I will improve upon it. And when I have done so, you will let us go.”


Sister wondered what it would look like, if she could read Third Drone’s programs at that moment. Would she see a lie within them?

“I will require metal,” said Brother.

Third Drone huffed. “This will be acquired.”

As they turned, they flapped their stolen wings. “The wing base must remain the same,” they said over their shoulder. “The wings must connect the same way. This wiring is not optimal for me.”

“I will keep the base.”

Third Drone tapped the wall and Sister’s bars dripped open. “Then we will acquire metal.”

Third Drone knew of an abandoned mining base on one of Chrysale’s outermost moons. They moved the ship to the rings of the lesser giant in Chrysale’s shadow, but would not approach the gas giant with it. Instead they snatched up Sister’s carry bars and flew her to the base, a long and weary way.

“It would be easier, if the ship were closer,” said Sister, as they approached the moon. It barely deserved the name, a moonlet so small that it could not keep more than a few molecules of atmosphere to itself.


Third Drone does not wish for the ship to get too close to Chrysale, thought Sister. Interesting.

The mining base was interesting, too. The equipment was old and corroded, but many of the parts were designed to be moved by taloned feet. The great bay doors would accommodate mining equipment, but the smaller doors into the base itself were wider than they were tall and had no stairs. Some were in the ceiling and the floor. Designed for beings with wings, thought Sister, even as she chewed away at the metal frames of the doorways.

Third Drone had known how to fly. Third Drone had a design for wings for use on Chrysale. Third Drone wanted wings to use there again. She piled the facts up, like stones in the hopper, and fed them through.

They have come from Chrysale, where there are other winged and taloned robots, but somewhere, they lost their wings. And they do not want whoever remains on Chrysale to see their ship. They want larger and better wings for their return.

When her storage bays groaned with the weight and richness of metal, Third Drone snatched her up again. She dumped the load on the deckplates of the ship and Third Drone picked out the choicest bits and offered them to Brother through the bars. Then back again, over and over, hour after hour, day after day while Sister used metal to expand her storage. She learned to be selective over the metals she harvested. That was a strange sensation. She had never had enough metal to be picky before.

She also noticed that Third Drone was standing watch while she dismantled the base. Their sensors scanned relentlessly, mostly upwards, keeping an eye out for an enemy that did not come.

Could I find a way to send a signal to Chrysale? If Third Drone fears the others like them, could I summon them?

She toyed with this idea, then discarded it like common iron. No. There was no proof that whatever came for Third Drone would not wish her and Brother harm as well. Eventually she decided to simply ask.

“What do you scan for?” she said.

Third Drone did not let up their sensor barrage. “I watch for activity from Chrysale’s upper atmosphere. If you sense any, inform me at once.”

“The ones who owned this base?”


“Would they object to it being dismantled?”

“You ask too many questions,” said Third Drone, and that, too, was interesting.

At last a day came when the great nanite wings that Brother had sketched became more than sketches. Alloy bones fanned out and great webs of flexible metal ran between them, like metal lace. “The old design had a fixed grid,” said Brother. “This one allows the user to widen or narrow the openings in response to the atmosphere.”

“Yessss,” said Third Drone. “Yes. Give them to me.”

“I need more space to complete them,” said Brother.

Third Drone hesitated, but there was no guile in Brother and they knew it. They let him out of the cell and Brother lay down flat on the deck, fanning out his new wings, and the nanites rushed to finish the job, extending the wings, polishing away rough patches, attending the thousand infinitesimal tasks. Sister watched in silence, observing the work, watching Brother’s shell vibrate with exhaustion as he spun himself out into the beautiful wings that he would never use himself.

Then they were done. The nanites severed the connection and they fell to the deck, gorgeous and dead. Brother fell too, exhausted from his work. Third Drone swept them up, then opened Sister’s cell.

“You will use them first,” said Third Drone. “And if they fail, you will be destroyed.”

Brother made a small sound of protest. “She is not made for the gas giant’s atmosphere.”

“Give me metal,” said Sister, “and I will build myself a shell to withstand it while we travel there.”

Third Drone assented. They carelessly ripped a panel from the wall, then another, leaving the corridor’s circuitry gaping open. “Eat,” they said.

Third Drone does not plan to come back, thought Sister. They do not care what becomes of their ship now. She ate.

“Brother needs energy,” she said. “He cannot recharge from the stars here. Allow me bring him to the sun scrap—”

Third Drone ignored her. They swept up her carry bars in their talons, and Sister saw Brother’s lights dim behind her.

I was right not to trust them.

She spent the flight in silence, preparing her shell for the corrosive winds of Chrysale. Preparing, too, for other things.

The pebble is black.

The gas giant spread out before them, green as poison, surface rippled with violet storms. As giants went, Chrysale was not large, but even a small gas giant is still only one step below a star.

“Your people come from inside Chrysale,” she said. “Don’t they?”

Third Drone’s sensors were trained on the planet. “They do.”

“It was they who built the mining station.”

“It was.” Carelessly. As if it no longer mattered what she knew. Third Drone held Brother’s new wings against her sides.

“You must give me a moment,” she said. “The connection you require is different than mine. Let my nanites adjust it. I will adjust it back for you.”

She had no warning. Third Drone’s silver tendril whipped out and caught at a port above her hopper, forcing a connection between them. She felt the alien machine’s thoughts driven into hers, demanding access to her logs, overriding will.

“Tell me the truth,” ordered Third Drone.

But Sister had prepared. She had buffered her mind the moment that she had learned to lie. She had spent the flight over strengthening that buffer and making sure that the false Sister was up to date. Third Drone’s thoughts went squirming across her mind, demanding to know whether she meant harm or deception, running hundreds of simulations where she returned from Chrysale and handed over the wings, testing each one for betrayal.

The pebble is black.

The pebble is black.

The pebble is black.

Third Drone gazed into Sister’s soul and the false Sister gazed back.

“Do it,” they said, withdrawing the tendril.

She ran her nanites up along the wings, tasting the familiar spaces of Brother’s engineering. Light. Graceful. Strong. She would have designed them differently, with a dozen failsafes, preferring power to elegance. She could never have made such magnificent wings of alloy and starlight herself, but neither would her plan have worked on any design that she would have made.

“Go,” said Third Drone. “The upper atmosphere only. If you do not return, I will go back to the ship and your companion will suffer for it.”

“I will return,” said Sister, and that much was true.

She spread her new wings and flew.

The upper winds of Chrysale were stronger than anything she had ever conceived of. This was nothing like the thin atmosphere she was born in. These winds were like solid things, like a landscape spread out before her, with peaks and valleys, walls and sinkholes. Her sensors were nearly useless against the weight of the storm. No wonder Third Drone’s sensors are so powerful, if they developed in this.

Sister was not the flyer that her brother was, but his wings did not fail her. When she needed lift, the grid flexed with exquisite grace, increasing her resistance, and when she needed to dive, the holes opened farther, wind flowing through and over them. They practically flew themselves. She felt Brother’s fierce joy of flight and understood it as she never had before, even as she feared what lay beneath the upper winds.

She surfaced from the atmosphere and rose. The shock of vacuum on her wings felt like a sunrise.

Third Drone landed on her back, talons thumping against her plates. “They work. I saw you. Give them to me.”

“Let me rewire the connection for you,” said Sister.

She was slow and thorough. Third Drone fairly trembled with impatience above her. At last, she severed the last connection and the wings were cut free of her body.

The pebble is black.

“At last,” hissed Third Drone. “At lassssst. They cast me out and took my wings, but I will return, and I will be more glorious than they ever were. They will bow down before me and I will unmake every one of them who watched as I was torn apart.” Metal squealed as they ripped Brother’s old wings free and pushed the new ones into place.

Sister watched the old wings drift away, and then, a moment later, Third Drone dropped her and she too drifted free.

“I cannot fly,” she said.

“I do not care,” said Third Drone, and dove into the surface of Chrysale.

Sister nodded to herself. This, too, she had expected.

She waited for thirty minutes. That seemed long enough to her. Third Drone was impatient and would be deep in the atmosphere by now. Deep enough that her last, tiny adjustment would have become obvious.

Brother had worked in good faith. He could not do anything else. But Sister’s nanites had plucked the web of connections. One adjustment to the wing grid worked. Ten worked. One hundred worked.

At one hundred plus one, the grid snapped open to its fullest extent and stayed there. For Third Drone, it must have felt as if their wings had suddenly become nothing but bones with no web between them. They would no longer soar. They might attempt to control their course with thrusters, but the thrusters, too, no longer responded.

She had not had the heart to sabotage the great wings themselves, but the base, designed to fit into Third Drone’s shell, was not her brother’s design. She altered it with a glad heart, under Third Drone’s eyes, and sent a million gallant nanites off to their doom and her salvation.

Sister wondered what Third Drone’s last thought had been. She hoped that they realized that it was not a failure of Brother’s engineering.

She wondered, too, what the inhabitants of Chrysale would think, when they found the wreckage of Third Drone. Criminal or heretic, she did not think they would be missed. Perhaps, if any part of the wings survive, they will be able to make use of it.

Her own thrusters were very limited things, useful only for moving her over outcroppings and depressions on the surface of an asteroid, but they were enough to work with here. She fired small pulses until she could reach one of Brother’s discarded wings with her gripping claws. It fitted into her side and her remaining nanites hurried to secure it into place. A single wing was clumsy, but it gave her enough thrust to reach the other wing, and then she turned away and left Chrysale behind forever.

As she flew back to the ship, she wondered if Father had sent a signal yet, telling them to return. She had a machine’s patience, and so it did not seem as if it had been a long time, but she remembered that Father had a different sense of things.

Brother was still lying where he had fallen. Sister dragged him out of the corridors into the light of the sun scrap, and sat beside him while he drank solar radiation through his skin.

His first question was “Did they work?”

“They worked magnificently.” She shared with him the feeling of that flight, the joy as the wings took on the winds and won.

“And Third Drone…?”

“Has gone and will not return.”

It was not a lie, but it was not the truth either. The truth was too large and to understand it would require Brother to become something other than what he was. I prefer him as he is. If one of us must lose their innocence, let it be only me.

The pebble is black.

“Come,” said Sister. “Let us learn how to steer this ship. Father must be back from his treatment by now, and we will go and see him again.”

“What if he is not there?”

“Then we will go and find him. We have plenty of metal now, and a ship.”

Brother nodded. She reached down her gripping claw and pulled him back upright. He stood patiently while she reattached his wings, and then they went together, through the house of metal, to find a way to return home.


(Editors’ Note: “Metal Like Blood in the Dark is read by Erika Ensign on the Uncanny Magazine Podcast, Episode 36A.)


T. Kingfisher

T. Kingfisher has written novels, comics, and in another life, children’s books. You can find her work at She lives in North Carolina with her husband and hounds.

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