Work Text:
They cannot falter in the face of the villagers.
Gen knows this because he has been a performer his whole life. If you asked him why no hesitation can show on their faces, he would smile that smile that stretches his cheeks—not as round as they used to be, all that baby fat lost to unforgiving millenia and the realities of a world of stone—and know exactly what answer to give.
Senku knows this because he is seventeen-eighteen-probably-not-yet-nineteen, and he never learned how to falter. If you asked him why the villagers must never see him doubt, he would smile too wide to be anything but a joke, and say that there’s nothing to falter from. It’s science. That’s all it needs to be.
So in the light of day, Gen’s questions are carefully placed, designed to egg Senku on. When he talks to the others, Senku’s plans all weave themselves around Gen, as if Gen is their only constant.
After that cornering in the dark of the woods, Gen wakes up beaten and starving, to Senku with his hair tied back, his dark-ember eyes tired and unyielding. Gen had been dreaming of light, of electrified metal. Senku looks at Gen and the only thing either of them can think of is lightning—whip-bright crack across the sky, finding exactly the most perfect way forward. Gen’s always had an uncanny sense for good collaborators, and Senku must know it too, when he leans down to whisper in Gen’s ear. When Senku says ‘cola’, it sounds like the whisper of a man talking to himself.
It doesn’t ever stop being a joy, exactly. Senku is a scientist through and through, and the day he faults someone for not knowing what a pulley is is the day he ceases to be one. But then Gen twirls in, with his illusory magic and toothy scar, and it’s like relearning a language he spent a childhood speaking, or finding himself back in a house he used to call home. Even the creaking of the floorboards sounds like the groan of his name, sounds like a name it has known for years.
“You call this ramen?” Gen complains. Senku had offered him lunch. Gen hadn’t quite refused. “I think I can taste grass in this.” It’s at least his second time eating it, but like Senku, he’s stuck imposing what this is supposed to be over the steaming bowl in his hands.
“I can call it whatever I want,” Senku says. “They’ve never had proper—”
“Don’t say proper like that,” Gen interrupts. He pokes the noodles with his chopsticks. “You’ll make me think you’re a snob.” Here by the sun-soaked rock where they’re eating this meal together, Gen’s voice grows low, unhoneyed.
“None of them know it can taste any better than this,” Senku amends, sympathetic. “I—It did what it was supposed to. They let me in. Practically dropped all that manpower right at my feet.”
“None of them know,” Gen agrees. “No one knows except me and you.” Then Gen’s eyes flick up, meet Senku’s, and his smile is faint, but true.
Senku won’t call it relief. He won’t even call it trust. It takes getting to know someone to trust them. This isn’t knowing someone. This is Gen, watching him and sealing his every secret behind that pearlescent grin. This is far more than knowing someone.
“I’ve got some friends in the Kingdom of Might who know. It’s not no one. And it definitely won’t be no one when we’re done reviving everyone.” Senku eyes Gen’s bowl, how the volume of soup hasn’t changed. “You don’t need to pretend to eat for my sake, mentalist. If you want to starve while you work the forge, you can just say so.”
Gen drums his fingers on the side of the bowl. “I’ll eat it. Give me some time.”
Senku snorts at that. He’s almost surprised to hear that it makes Gen chuckle too.
Senku finds Gen crouched like a dirty thief behind the lab.
Gen isn’t so undignified as to scramble to his feet right away. He starts by looking up and chirping, “Hello, dear!” Then he stands, an exercise in unhurriedness.
“Hey.” Senku’s gaze is utterly piercing. Gen is too good a magician to fidget with his sleeves, but he feels his smile go rigid, and is sure Senku sees it too. Gen can’t quite tell if the feeling in the back of his throat is bile or dryness.
“Wanna see?” Gen coos, before Senku can say anything about it out loud.
Senku tilts his head at the pouch Gen pulls out from his robes. Inside is a dark red liquid that doesn’t quite slosh when Gen moves.
“Fake blood,” Senku says, a tinge of surprise.
“Pretty good, right?”
Senku hums, but doesn’t answer, taking the pouch to sniff the concoction inside. Gen, watching, feels the full weight of his own long sleeves for the first time in a while. Senku’s arms are always bared to the sun, veins exposed, and all Gen can think is that it would be so, so easy—
“Something wrong?” Gen asks, leaning a fraction closer. “You seem distracted.”
Senku makes decisions as quick as breathing, whole plans falling into place in the space of a gasp. He says, “That meathead’s not going to come after you again. Not while I’m chief.”
Gen takes the pouch back, puts it away. Maybe all scientists are like this and he just hasn’t met enough of them. Or maybe it’s just Senku whose mannerisms he’s learning like the ridges of his own knuckles. “I know, dear. But we have no shortage of enemies, and I’d prefer to get out of this alive. I imagine most of these people do.”
“Hm. Worried?” Senku asks, a burning smile cracking across his face.
“Never,” Gen says with a grin. Senku doesn’t call him on the lie.
This place has terrible fire-safety, Senku had joked once, looking over the straw-roofed huts of the village. He’d spared only a moment’s thought for it back then, imagining furnaces and pale steam against a snow-bloated sky. What he gets is smoke, and it arrives far too soon.
Later, long after the fires are out and the last wailing children have been soothed and Senku has stopped mentally tallying and retallying their dwindling medical supplies, Gen slinks over to Senku’s side. He bumps their shoulders together and says, “What’s that face for? Didn’t anyone ever tell you this is the best humanity has to offer?”
“No.” Senku narrows his eyes at the air, can’t tell if the fire he smells is a conjuration of his frazzled mind, half a leftover dream of the old school labs, or something about the air of this place, always on the verge of being ablaze in one way or another. “No one’s ever told me that, mentalist, because it isn’t true.” He picks up the bucket at his side just for something to do. “No one was ever dumb enough to lie to my face until you showed up.”
Gen smothers a sound into his long sleeves that might be a laugh and might be a sigh. “In case of emergency, climb out the windows.”
“At least that’s pretty easy, without anything covering them.”
“Terrible plan to use so much straw though.”
“That’s exactly what I’ve been saying.”
Gen’s days in the village are bright with sun, the kind of days other people, in other times would describe as perfect. They hurt his eyes. Gen curls and uncurls his fingers, grimacing. Like spotlights. Somewhere along the line, he must have forgotten the difference between being on-stage and off.
He dumps a basket of torn nets in the shade where Senku is eating with a distracted gleam in his eyes. “Do you mean the things you tell those poor people?”
Senku cuts Gen a complicated look, too ready. “Use that clever magician’s brain of yours.” A pause that is deliberately filled with the sound of slurping. “How much of that do you really think I believe?”
“I think you believe every word of it, Senku dear,” Gen says without looking at him. He picks at one of the nets. “I think, despite all your insinuations to the contrary, you’re only human. I think you’re a hopelessly naïve, ridiculously idealistic high schooler, and you just happen to have the brains to drag all of these people into your pipe dream with you.”
The bowl is set neatly on the ground, empty. “I’ve only ever been someone that happens to like science a lot. I didn’t lie about that.” Senku’s tone is level, undefensive if you look at it from the right angle.
There’s an artist Gen is thinking of. Rooms and rooms of infinity mirrors, boxy traps that promise the endless. A thousand visions of yourself, disappearing into a horizon that’s barely past the edge of your fingertips. Senku turns to Gen and Gen half-expects the ripples of a disturbed reflection.
“Whose side are you on, mentalist?” Senku asks, eyes narrowing.
“I’m just playing devil’s advocate,” Gen says sweetly. Senku frowns at him.
“If you’ve got a problem—” Senku starts. Then he must realize there’s no way to finish that sentence.
“Don’t worry,” Gen purrs, reaching out to tap twice on Senku’s arm. “I mean it. I’m really just asking.” His smile widens. “You made me cola, after all.”
Senku’s eyes narrow impossibly further, but then he wrinkles his nose and says, too softly to be ungentle, “Talk about selling out,” and Gen laughs.
The autumn day is cool and brilliant. It will not last.
Like dissolves like.
Senku can feel the edges of himself blurring around Gen. In any other world it would be an uncanny kind of entanglement, him and Gen, because he extends his arm and it’s Gen that moves, Gen that smiles and lies and runs barefoot through the trees to reach that distant kingdom first. Some days, he and Gen stand next to each other and he could swear he feels Gen’s heartbeat in his throat, behind his teeth, against his tongue.
One night, when neither of them can sleep, Gen comes up to the ledge on the side of the hut they’ve both been sleeping in and brushes his fingertips against the exposed skin on the back of Senku’s neck. Senku can’t suppress the shudder that pulses through him.
“Your hair is soft there,” Gen muses.
“Get your hands off me,” Senku grumbles, scowling when Gen wiggles his fingers, visibly nowhere near Senku.
“I heard him say he broke your neck.”
“Did he?” Senku asks, as neutral as he can make it. He shifts minutely, makes room for Gen to sit too.
Gen shrugs grandly. “No, I guessed. He’s the kind of person who would want to make a kill clean. Quick.” Gen’s eyes are dark as coal. “Something about honour, I’m sure.”
Senku scoffs, and puts a hand on the back of his neck without thinking, and then curses himself for his own stupidity.
“I won’t tell,” Gen promises. He doesn’t move, and neither of them are touching, but Senku can sense him there as clearly as he can sense his own hands. “As long as you don’t tell either.”
That’s an easy agreement to make. They are bound by hundreds of them, and Senku fell into every one effortlessly. “Blood isn’t really as viscous as that sugary stuff you have. Remind me tomorrow, I’ll get you some red water to mix with it.”
Gen laughs quietly. “You know, there was a second there I thought you were going to say you’re going to get me some real blood. I don’t think I would have been all that surprised to learn you’re a vampire, if not for how often I see you in broad daylight.”
“Vampires aren’t real, mentalist.”
“If you had asked me a year ago, I would have said there’s no way someone like you could be real either.”
Senku feels the smile stretch across his face, helpless to stop it. “Three-thousand seven-hundred and twenty years ago, more like.”
Senku is fiddling with wires, circuits springing to life under his hands. Somehow, none of it is magic. Gen keeps watching, keeps searching instinctively for the trick, the moment something slips out of Senku’s sleeve or disappears beneath Senku’s palm. But there’s no trick, except for the ancient, ancient trick of electrons scattering across atoms like a string of dropped pearls.
Senku hasn’t chased him away yet, even though there’s no way he hasn’t noticed Gen looking.
“You went to high school. You know what electricity is.” Senku has an air of—It’s not disappointment. Gen pauses a moment to pick it apart.
Curiosity.
“You’ve heard me heap praise on you all day, Senku dear,” Gen murmurs. “I don’t think your ego needs any more inflating.”
“I don’t know what you’re talking about, mentalist,” Senku says, sticking a finger in his ear like he’s hoping that will make things clearer. His other hand nudges a strand of gold, gleaming, into place.
“We call this world a stone world, and here you are, darling, hellbent on making a cellphone. Any sensible person would be in awe. But, again, your ego doesn’t need inflating, so I’m not going to tell you any of that.”
Senku snorts. After a moment, he hunches his shoulders, an uncharacteristically unguarded gesture. “How else are we going to win this war?”
“When did we start calling this a war?”
Senku looks up from his circuitry at last, and Gen stares back. Gen has played people twice his age out of their life savings before. Senku can handle the science. Gen can give his best poker face in return.
“That’s what it is,” Senku says, after too long a pause.
Gen says, “You saved our precious village priestess’s life, didn’t you?”
Senku blinks, a twitch over his face that gives away his confusion regardless. “The drugs saved her. I just gave them to her.”
“You had medicine and you gave it to her freely.”
The beginning of a smirk curves the corner of Senku’s mouth. “Yeah. Freely,” he repeats. His eyes shine red-brown, like they’re looking into a none-too-distant future and seeing what the price of this will be already. “We’re going to do it better this time.”
“Someone else might call that hubris, darling.”
Something sparks in Senku’s too-bright eyes like a challenge. “Doesn’t matter what anyone calls it. I’m going to revive all of civilization no matter what it takes.” He goes back to his wires like this is not an impossible thing.
Knowing Senku, it isn’t.
Looking back on it, this part of Senku’s time in the village is split into fragments, alternating starlight and skies so blue they’re blinding. Gen finds his way into the cracks of every single one.
“And if I stick this on top—it doesn’t conduct—then we have a transistor!” Senku throws a triumphant grin over his shoulder. Gen fulfills the duties of his role impeccably, gliding over to look impressed at this development.
But then their usual script falters. Gen says, “Ah, that’s very clever of you,” and doesn’t ask anything else. That isn’t right. Doubly unusual, Gen waits barely five seconds before turning to leave.
“Gen.”
“Hm?”
Senku catches his sleeve and pulls him back into the coolness of the lab. “If you let this get in the way of your work for me, I’d rather just give you back to the enemy.”
Gen breathes. In. Out. Too slow to really be a sigh. “If you say so.”
Senku never finds out what went wrong that day. Time moves too fast for him to return to it. And there are other exchanges.
“The Chinese made some incredible scientific advancements during the…Han dynasty, I think. The compass, the seismograph…” Senku shakes his head. “I don’t remember much about it. History isn’t my strong suit.”
“Nor is it mine,” Gen murmurs. A mirthless smile. “And if you don’t remember it and I don’t remember it…”
“It may as well be lost to us,” Senku finishes the thought. “We’re all that’s left for now.”
Gen laughs, a sharp and bitter bark. “There is so much we don’t know, my dear.”
“We have enough. We’ll make it be enough.”
Gen blinks at that. “What a funny kind of faith you’ve found,” he says, soft enough to love.
“Stop looking at me like that,” Senku grumbles. “You’re hardly much better than me.”
They leave it at that.
They keep circling each other. The easy metaphor would be sharks—the old movies, the cyclical motion of their dorsal fins nearly hypnotic. Tasting something saltier than the usual tang of the ocean spray, finding something like a promise in the way the light strikes the foaming waves.
Really, the way he and Gen find each other, again and again and again, is more like a gear, pulled back by its teeth to the same place with every turn. Despite himself, Senku never finds himself wishing to escape it.
“Come to think of it, I haven’t had fries in centuries.”
Gen groans, hides his face in a sleeve. “Why would you bring that up? Now I’m going to be thinking about it. Senku dear, what if we just never get to have fries again? Wouldn’t that be the worst?”
Senku laughs, can’t help it. Some passersby are giving the two of them funny looks, but truly, who cares? “We’ll have fries someday. I’ll make them myself.”
“You know how to make fries?”
“One billion percent.”
“A boldfaced lie,” Gen mutters. “No one in this stone world would even know what they are. I miss—” He makes a face, subtle, because Gen is a performer down to his bones and a professional to boot. Senku only recognizes the look from practice.
“What?”
“Never mind. You know the feeling, don’t you? When you think about the past?”
“I—” He almost lies again. “Yeah.”
Senku is thinking of silver-black hair, and stubble that scratched at his face when he was young. Of a pink-red ribbon wrapped around a tree, and a quiet promise to walk each other home no matter how late their club meetings went. Of eyes that are so brilliantly warm-brown he’s sure the exact shade will always be etched somewhere in his brain, and a half-feral old cat that everyone agreed was ugly but that lived like a king for a week before finding a proper home elsewhere.
Gen is a poor substitute for all that. There’s no doubt in Senku’s mind that Gen is looking at him and thinking the very same thing.
The observatory is one of the few places in the village that gets truly empty at night. Under the stars, the hot coals lodged in Gen’s ribs become one massive ache. The observatory is, reliably, where he finds Senku.
Tonight, Senku is slumped at the telescope, eyes like banked embers, dull and unseeing. “The constellations have moved.” Even his voice, Gen thinks. Even his voice resonates at just the right timbre to exacerbate the ache in Gen’s bones.
They sit next to each other, shoulder to shoulder. Nights like this, the whole village disappears. Even the sound of snoring is muffled by the planks and the snow. Nights like this, Senku must feel the hollowness in Gen’s chest as acutely as Gen does, because he always has something ready to talk about.
“There’s an algorithm,” Senku starts, “for determining if a year is a leap year. A combination of some conditions about what the year is divisible by. It’s a bit more complicated than a lot of people think, but in code, it’s not that hard to write out. Implementing it was one of the first things I learned.”
For someone like Senku, ‘one of the first things’ he learned was probably from more than decade before the petrification hit. Scientific geniuses are jerks like that, Gen decides. They know too much, and too little. Both of those things manage to be true at once, and Gen has never learned to sit comfortably with paradoxes he can’t control.
“Tell me something else. I’m tired of missing computers.”
Senku huffs, leaning his head against the wall of the observatory. “Missing things gets so boring. Don’t people get sick of being sad after a while?”
It’s one of those nights where Gen can take Senku’s hand without Senku flinching. Gen idly runs his thumb over Senku’s knuckles. A long, pale-pink scar curves along the back of Senku’s hand.
“What’s this one from?”
Senku blinks at it, and then smirks. “Our resident warrior is really good with a katana.”
Gen hums thoughtfully. They both recognize that this means something, and neither realizes that the other doesn’t know what it means either.
“Any closer and she would’ve cut my hand off.” Senku laughs like there’s anything funny about that. “I would’ve needed a prosthetic. Or maybe I would’ve just bled to death.”
“What are the odds of that?”
Senku shrugs, careless, and Gen wants to ask a different question entirely.
How many times?
How many near misses? How many ‘just-lucky-enough’s? How many times did Senku stare the whole wide universe down and decide, no, it will not happen this way?
“Do you believe in luck?” is what finally comes out.
“Who needs luck?” Senku says with that brilliant and terrible grin. “I have science on my side.”
Someday in the future, Senku will give some variation on this line, and Gen will say, “That’s just to cover for the fact that your luck is the worst, isn’t it?” But not tonight. Tonight, they fall asleep under the stars, and in the morning, they’ll act like it never happened.
The winter is long. They end up having the second half of that conversation, about things given freely.
They’re in the lab, long after dusk has come and gone, stretching shadows and beckoning out the constellations. They’re all so busy these days that even now, Senku’s fingers are smeared with oil, Gen’s palms stained dark by dirt and soot. The lab smells acrid. Curtains have been pulled across the entrance, but they don’t reach quite fair enough to do much more than dampen the chilly winds.
Gen’s clothing rustles, layers on layers to make up for the absence of heat. “Do you want to know why I asked about that medicine you made?”
“Don’t tell me something you’ll regret saying, mentalist,” Senku says.
“I have a story that might make things a little clearer,” Gen says, not a prompt in any way he’ll admit but a prompt nonetheless.
“Yeah? What’s that?” Senku asks, if only for the familiarity of the lines.
The story Senku is expecting is the kind Gen always tells to the villagers. Abstractions of stories from their lives in the old world. Outer space becomes ‘the place above the sky’, cars become ‘moving metal beasts’, Gen and Senku become some other people, from other places, with other names. It’s easier when none of it is recognizable.
But Gen isn’t in the mood for fairy tales, it seems. There’s no poetry or personality to the way he says, “Artemisinin was once used as a treatment for malaria.”
“So I’ve heard,” Senku drawls. “You remember who you’re talking to?”
“This is an old story, given the pace of things back then. A team of very clever scientists pulled off something remarkable to do with it. Did you hear about that too, dear?”
“University of California. Berkeley. A modified Saccharomyces cerevisiae yeast. Spit out artemisinic acid, so we could turn it into the medicine.” Senku pauses, setting down a container of sodium hydroxide and rubbing his hands together to warm them. “You’re right, that is old news. I’m surprised you know it.”
“What would you have done, if you were on that team?”
Senku snorts. “You already know what I’m going to say. Get to the point, Gen.”
“The price of artemisinin used to fluctuate wildly, because it depended on farmers being willing to grow the plant they needed to make it. It was an expensive and time-consuming task. You know something of this.”
“So do you,” Senku replies easily. He huffs as the candle begins to waver, low and uncertain against the draft from outside. Gen hops off the table he was perched on to fetch another.
“So they found a way to make it that doesn’t rely on those farmers and those plants. After that, it should have been easy.” Gen dusts off his hands and clears his throat. “If it was just a matter of finding solutions, or testing the edges of what we can do—”
“This is a boring story, magician.”
Gne gives Senku an appraising look. “The patent for insulin was sold for a dollar so it could be given to as many people as possible. You remember how that turned out? We started playing with chemicals and we turned them into weapons, dear Senku.”
“The other option is to let ourselves be killed,” Senku says evenly, gesturing to the neat rows of beakers and jugs on the shelves of the lab. “Have you forgotten where you are? Three-thousand seven-hundred years. Quit dreaming of things that are long gone.”
They can needle each other from angles only they know. Gen does that thing again, that thing where he’s breathing and on anyone else, it would sound like a sigh. To Senku, it just sounds like breath. Your lungs don’t move under your conscious control.
“We don’t have time for this, Gen.”
“Why? Why…?” But Gen doesn’t finish the question.
“There’s this story,” Senku begins. “It’s probably apocryphal. A doctor. He’s dying.”
Gen’s mouth twists. On any other day it might’ve been a smile.
“This dying doctor. He was… counting. Announcing his heartbeats as he felt them. These people around him, I— I can’t remember if they were trying to save him. I don’t remember how many they said there were.” Senku’s never admitted to this many failings at once, since arriving in this village. “I don’t remember what killed him.” He pauses.
Don’t make me finish this story, Senku thinks, a brief flicker of inexplicable panic. Then, when he sees Gen open his mouth: please, let me finish this story.
“Okay,” Gen murmurs into the silence.
“He had his hands,” Senku gestures, demonstrating by setting two fingers on his wrist, “like this, counting out his pulse. He was a doctor, you know? It must have been pure habit at that point. You do what you can first and sort out what you can’t do after. It’s—” Senku puts his hands down. Breathes. “The doctor’s last word was ‘Stopped.’”
Sometimes, Senku turns mid-story expecting to see Gen and finds Ukyo or Nikki instead. Sometimes, Gen bows at the end of an after-dinner magic display for Ruri and is thrown by the absence of Senku’s voice picking apart his methods of trickery. Sometimes, one or the other coughs into his hand, swallowing the name that had been waiting on his tongue out of sheer habit. Most of the time, it’s easier. Words like microwave and skyscraper are no longer archaic relics but a living extension of the strange, cobbled-together language they’ve built with the villagers. Senku and Gen aren’t ghosts anymore, haunting late nights in the observatory.
The Kingdom of Science is livelier than ever. But Gen remembers the feeling. Senku remembers their talks. Sometimes, they catch each other’s eyes, and think, somewhere below conscious thought, somewhere swimming with promises and threats half-formed and instinctive, No one will ever know you as I do.
And then they grin at each other like real friends, and carry on, changing, unchanged.