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It starts, as most things do, with curiosity.
This is true for both of them, Ryuusui thinks, because he hasn’t known Senku long but knows him well enough to understand that’s the foundational principle of everything Senku does. The only thing that matters, right next to the conviction that Senku can (and will) give Ryuusui what he wants. And behind curiosity and satisfaction, it’s all one long collective list in the tertiary. They’re mostly the same, after all.
“You’re the first we’ve encountered with petrification marks in an area of massive receptor concentration,” Senku says, back half turned so he’s getting as much light as possible from the open laboratory doorway as he stares, unashamed, at Ryuusui’s hand. “So let me touch them.”
Ryuusui raises one eyebrow. “Yours are on your face, if you haven’t noticed. Plenty of nerves there.” He’s unsure if this is another test—like the wood and the weather. Still, Senku seems plainly interested, though in that strange, uninterested way he has. Like he’d find some new toy soon enough if Ryuusui didn’t rise to the bait. Ryuusui thinks Senku could charm the stripes from a cat—or simply ask for them, honestly, and the result would be the same.
There’s a twitch at the corner of Senku’s soft lips, unchapped despite the general outdoors of their whole lives, and Ryuusui wonders what other small luxuries Senku has returned to mankind that he hasn’t thought to ask about yet. He’s heard the story from Taiju more than once—soap, the first major step toward progress after the three major H’s of survival: hunting, hydration, and a hut. He only has to glance around the Kingdom of Science as it stands to understand there’s a similar appreciation for comfort at work.
“Yeah, but—it’s different.” There’s not an ounce of doubt there. Barely a sliver of coy, too. Just bare-faced, confident honesty. “A similar number of nerve endings, but the priority placed on the variety of feeling isn’t the same.” Fair. So Ryuusui holds out his right hand and knows, in the way of men who have always carried themselves with the confidence of natural-born leaders, that he will never be the same.
Senku presses both palms and all ten fingers against him—props his elbow against the knotted wood of the table and carefully, carefully, traces against the thick-thin crust of his index finger. Against the callous of his knuckles, half obscured, and against the knot of scar tissue ridged at his joints.
Ryuusui shudders, even though he can't feel it—shudders around the sight of Senku’s captivation, deep and intimate and beautiful.
“Exhilarating,” Senku says.
“I should hope so,” Ryuusui replies, phlegmy, because I want you feels a bit too on the nose.
“No, I mean—” Senku glares at him, intolerant. He deserves that. “You can't feel it, right? It’s like a layer of scar tissue—like the rest of us, mostly dead.”
“In so many words.” Ryuusui nods. Swallows. Because it's true enough—he can't feel it, the touch. Can only see the concentration surrounding it. The single minded focus. The gift of Senku's full attention, a rare thing, caught in the moment like the board-pinned wings of a dragonfly or like the washi sails of a model ship encased in glass. Like Ryuusui is just a thing to be writ, a kept fascination.
“Your fine motor skills remain unimpacted,” Senku murmurs. It's to himself now. “Your dexterity is above above average and your sense of—” a strange pause then “—pressure control carries the finesse even beyond someone with full range.”
“The finesse? Poetic for you, Dirac.”
“Don't insult me.”
“Do you enjoy the minutia of my—” Ryuusui moves, then, to grasp Senku's chin with his other hand, and Senku smacks him away. “—pressure control.” Returns to his notes.
“I enjoy the expertise behind it.”
“The expertise?"
“Freaks with talent are rarely boring,” Senku makes some quick-handed scrawl on his paper even as the hand left lowers the ridge of Ryuusui’s middle finger. His longest. His deepest, all double entendre in Ryuusui’s own head like a fool.
And Ryuusui laughs, mouth hitched into half a grin. “Like Tsukasa,” he says, and that gets the sliver of Senku’s attention he’s lost to his body back. Senku doesn’t turn his head, just cuts his eyes back at Ryuusui for a second, unreadable to anyone who hasn’t spent a lifetime figuring out what people really want.
“Like anyone who catches my attention,” Senku lies, and Ryuusui lets him.
Thumbs press into Ryuusui’s palm and Ryuusui reaches up again to cup Senku's chin, gentler this time, and this time Senku doesn't even blink—just stares back with unimpressed, red, knowing eyes and Ryuusui has sharp teeth but Senku has something worse—a strong bite. The stubbornness not to let go. The confidence (genius, without question) to trap him in the first place, on Senku’s own terms.
“Well, you certainly have mine,” Ryuusui says.
“Sucks for you,” Senku replies. Grabs his hand by the wrist, not strong but precise on the tendons in a way that forces Ryuusui to let go. Sticks those two cracked fingers in his mouth and runs his tongue along the ledge of them and then sucks at the skin there once, hard, just to the edge, just enough to leave an (oh, oh) impression. Then lets him go, just like that. “Because mine’s hard to keep.”
Ryuusui swallows and, whether Senku notices at all, knows it’s utterly game over. Forever. “That was highly unnecessary.” Senku’s already turned back to writing.
“Don’t be a prude, Captain.” Somehow he makes the title sound like an insult. What’s a captain to a king, after all? “I can’t lick my own and I’m not sucking face with Taiju because he’d find the whole thing too funny—and anyone else is out of the question—so it was, in fact, highly necessary.” Senku doesn’t stutter once, voice entirely even, and Ryuusui thinks he might’ve found the only other person on earth with just as much shame as he himself—which is to say, very little.
“Fascinating.” Ryuusui leans forward, curling his fingers around the hand still holding his. “You’re fucking with me.”
And Senku waves him off, slips out easily, and flicks Ryuusui’s forehead all without looking. Ryuusui grins. “I can’t definitively confirm if there's a mineral element because we're not nearly to that level of equipment—years from any kind of actual spectroscope, much less a spectrometer—but there’s an ultra-distinct taste to them—metals and other rocky material. Totally inorganic. It’s why the zinc and iron in blood’s so distinct to the senses.”
“Not copper?”
“I mean, there is, but not much. It’s a common misconception born from the fact that most copper-plated currency is, in fact, just that.”
“You really do know everything, don’t you?”
Senku looks at him, then, and Ryuusui just flexes his fingers between them—hand still held up in case Senku needs it again. Hopes beyond hope that he does, and relishes the uncertainty of it all like an addict spinning roulette. Senku rolls his eyes. “I really don’t.”
“Well, I’m here to support the advancement of mankind however I can.” It’s not a lie, technically—the advancement of mankind is the advancement of Ryuusui, after all. And he’s here, specifically, for the advancement of Ryuusui.
All his life he’s been thought an empty-headed pretty boy with too much money and too much ego, and most of that’s true: he’s very pretty and there’s no such thing as an overabundance of either other option, in Ryuusui’s humble opinion. He’s been plied with wet-edged smiles and slick palms and a perpetual cloud of condescension, and Senku—Senku couldn’t give a shit whether Ryuusui likes him or not.
Ryuusui can’t remember the last time anyone touched him with so much sincere tenderness; not the oxymoronic, careless care of simpering businessmen or sweating reporters or wannabe sugar babies, but something with the kind of deliberate, clear understanding that Ryuusui himself is the person on the other end, not just everything he represents.
Francois had been right of course—they always are.
I have to have him, Ryuusui thinks.
“I want you,” he says instead. Finally. It is a little on the nose, but he’s always been straightforward.
Senku’s response, “Tough break,” is predictable and a significant part of the whole appeal in the first place. The more interesting taste is always, always the one he’s not allowed.
Ryuusui wants to win, of course, because he’s very used to winning—it’s a hard habit to break and it’s one he doesn’t intend to, lest he stop winning in the first place.
Except.
Except from the first time he’d heard the word Tsukasa from Senku’s mouth, he's known he won’t. That he's lost before he even had the chance to play. Lost by virtue of Senku’s bad luck, petrified so close to Tsukasa in the first place—petrified so far from Ryuusui himself, thousands of years ago.
Ah, well.
He’s never given up anything gracefully in his whole goddamn life, has he?
The balloon is just the beginning, of course. Then there is the fashion show and the mine carts and the worst bread they’ve ever had in their lives—and there’s getting their collective asses kicked by Francois for that last one, specifically. There’s the giant drawing mechanism he builds on the beach and then doodles with it (of all things) and there’s chocolate that almost tastes like the real deal and there’s—
Senku skids only halfway to a halt in the ice outside his hut (Ryuusui really should have done something about that) only saved from a faceplant by Chrome’s fist on the back of his collar and the way he hits the door with half his body, throwing the whole thing open. Ryuusui barely has time to look up from the blueprints on his desk before Senku wheezes—
“Dude, do you know how to snowboard?” red-cheeked and excited.
“Of course I know how to snowboard,” he answers without hesitation, blinking back, quill still half-raised. “What are you—”
“Perfect.” Senku’s expression is utterly maniacal with glee and it does something phenomenal to the pit of Ryuusui’s stomach. “Because I don’t.”
Chrome giggles and that’s less enticing but funnier, too, in its own way.
“I assume you want me to teach you?” It wouldn’t be the strangest request Ryuusui’s gotten since his revival, but it’s certainly unusual. In the corner of the room, Francois has already put down their mending and started gathering Ryuusui’s thicker fur-lined outerwear.
Senku looks at him like he’s stupid. “Fuck no—”
But Chrome’s already talking. “We’re working on a way to reduce the number of times we have to haul the sleds back up the mountain if we’re not transporting any actual supplies down the mountain in the first place and I have a theory we could take the runner from one of the bigger ones and strap it to a pair of shoes so it’s way smaller and more energy efficient and—”
“That’s a snowboard,” Ryuusui says.
Senku grins right back. “That’s what I said.”
Chrome still has Senku’s hood in his fist, ostensibly keeping him upright like a cat held mostly by the scruff, and shakes him a little, caught up in the excitement. “Can you people let me have anything?” He doesn’t even really sound mad about it, just a fond sort of exasperated like they’ve had this conversation a thousand times before. Probably have, Ryuusui thinks.
But Senku just laughs. He doesn’t look bothered by the violence, either. “Oh, no—it’s fucking genius.” It’s purely honest and perhaps also for the same thousandth time, Chrome preens. “The problem is that I don’t know how to do it.”
Ryuusui raises an eyebrow, already slipping one arm through the sleeve Francois has held out for him. “Make one?”
“No, you idiot—” Senku scoffs, and even Chrome starts to roll his eyes. “Of course I know how to make one—”
“Of course you do.” Of course he does.
Senku doesn’t even pause. “I just need someone to push down a massive hill really fucking fast who, like, probably won’t die.” He shrugs. “Because I would.” Then reconsiders slightly. Repeats, with emphasis, “Probably,” and Ryuusui thinks that’s probably ego talking and can’t help but respect the optimism.
It’s a credit to their professionalism that Francois finishes doing the coat buttons with one deft hand and thrusts a pair of soft-skin gloves into his raised fist, already poised to snap, with the other—already sure where this whole thing had been headed from the moment Senku burst through the door, long before Ryuusui himself.
“Ha! Then what are you waiting for, you brilliant bastard? Take me,” Ryuusui replies, utterly delighted, and Senku twists out of Chrome’s grip to cackle—
“Told you!” all smug triumph. “He wasn’t going to say no to that.”
Well, yes.
Senku could have led with probably won’t die and he would have agreed without question, all because Senku asked in the first place.
He goes to push them both out the door before they suck the rest of Francois’s furnace-warm air into the afternoon but somehow (somehow) finds himself dragged forward instead, strung along by a hand around his wrist. Take me, indeed. And (predictably) he does not die.
“He’s been in better spirits lately than the entire time I’ve known him,” Gen says, smile stretched around something political and multi-faceted in a way that reminds Ryuusui of leather chairs in board rooms. “There’s real joy there.”
In the distance, knee-deep in snow and ice, Senku and Chrome fiddle with a metal tube fitted across one end with a grate and a handle and—well, Ryuusui has a guess as to what it is, and hopes he’s right mostly because it’d be hilarious. They’ve cleared a wide berth around them both, the village long-since accustomed to the danger of new inventions, but with enough spectacle that of course there’s an audience anyway.
Ryuusui side-eyes Gen, who just smiles serenely back. “By my understanding, you’ve been at war the entire time you’ve known him. It’s only natural.” He likes Gen—really, he does. He likes most everyone in Senku’s kingdom, because he’s never found it very hard to pick out the good qualities in anyone—and he respects Gen even more for the intelligence kept hidden under a dozen layers of total bullshit.
Gen doesn’t seem the least bit put off, which Ryuusui also respects. “Maybe, maybe not,” he says, sing-song. “I’ve spent my fair share of time grilling our resident Senku experts, and based on the stories they’ve told—Taiju and Yuzuriha, you understand—I doubt he’s ever had anyone to match him.” Ryuusui raises an eyebrow, skeptical. “Both in mind and enthusiasm.”
Senku cackles with his whole body and it carries across the clearing as he flicks a spark against the end of the rod and instantly, fire shoots from one end. Chrome shrieks and Senku sounds like he’s been ripped right from the pages of a shounen manga—the villain’s team, possibly the villain himself. He’s made a glorified flamethrower and called it a snow melter (more for fresh water than anything, because snow shoes will get them over the fresh-crusted ice—) and it’s phenomenal. Ryuusui feels himself grin, doesn’t even try to hide his own laugh, and ignores the way Gen looks at him mostly because he doesn’t care.
“He seems well-adjusted enough,” Ryuusui shrugs.
Gen hums in return, and when Ryuusui glances over again he sees Gen’s turned, too, a look of fond exasperation tinged at the edge with worry. Senku wholly obliterates a snowbank into slush while Chrome practically runs circles around the whole thing. Then Senku does it again, to another, larger pile and Chrome demands a turn and after the pause Gen says—
“Who knows, really, but he was muted for a while, I think. Looking for something. Chrome has the enthusiasm covered.” Sighs. “And Tsukasa was, however briefly, equal enough to challenge him on the other front.” There’s something in Gen’s tone that brings Ryuusui up short—snags the edge of his attention. A wistful weariness. Regret, maybe, and the neon-bright past tense of it all, too.
It is the first time anyone in the entire Kingdom of Science has so much as hinted that Senku might not succeed—that Tsukasa is dead for good, no miracles and no scientific equivalent.
Ryuusui frowns; he isn’t sure how he feels about it beyond a strange, churning discomfort. Whether it’s from the suggestion of Senku’s failure itself or of what the aftermath of so much failure might be, he can’t say. All he finds is that he can’t bring himself to agree, not really.
“I highly doubt I’ll beat Tsukasa in his esteem,” he says because he’s not stupid. He knows that’s the real reason Gen’s egging him on in the first place, and Ryuusui finds it presses on a deep-seated bruise without warning. He’s always hated being treated like a chess piece more than anything else in the world.
For a kingdom, Ryuusui’s discovered Gen functions more like a consigliere than a counsel, because whether he’s king or chief or whatever Senku’s a handful himself. And it is, of course, the role of an adviser to account for every possibility and to ensure the prosperity of his—well—in the event of a worst-case scenario.
Still, though, there’s a melancholy tilt to the whole thing.
“Oh, none of us will,” Gen chuckles—good natured. Easy. Resigned without much disappointment, like he’s thought the whole thing over more than once and come to the same conclusion every time. For someone constantly working on a hundred different things at once, he’s surprisingly single-minded. “That’s why he needs someone new.”
Ryuusui chooses not to play along. Just watches Senku crank the lever on his certified threat to society as the flames turn blue. Any second, someone on the sidelines is going to get impatient enough to interrupt the whole thing, and then they’ll have an even larger problem on their hands. “Tsukasa must have left an impression.”
That earns him a scoff in return, and he can’t tell if it’s genuine surprise or another layer to the act. It’s intriguing, just like everyone he’s met in the last few months has their own specific flavor he’s yet to fully figure out. “I wouldn’t have pegged you for someone capable of understatement.”
“Understatement’s still statement of fact,” Ryuusui retorts. “And I’ve already made my decision.” Did a long time ago, in fact. He’s never been one to dwell on things, particularly when those things catch his attention in just the right way.
He doesn’t elaborate and Gen doesn’t ask him to. Just sighs, all theater, and says, “Do you think he’s going to burn a building down with that?”
And Ryuusui can’t help but snort. “I think he’ll be disappointed if he doesn’t.”
“I probably will too.” Gen waves one of his sleeves out in a broad gesture toward Senku—and, even further, the whole world around them. “Bonfires are lovely, aren’t they?” he says. “Spectacularly fun and, from the very beginning, so beautifully temporary.” And Gen looks at Ryuusui and Ryuusui looks back, unashamed.
“Hurt like a bitch if they get out of hand, too.”
Gen just shrugs, something equal parts teasing and true in the dark curve of his eyes. Sings, “Then you better not let that happen, Captain,” and turns away, entirely dismissive and entirely not. “I’d prefer he not have to sew anyone else back together because they’ve gone and done something stupid. Once was enough for anyone, even our dear Senku.”
Ryuusui sips his wine and watches Senku inspect the little model ship on the worktable between them and is grateful—infinitely—for the village elders. Though still mostly terrible, their reserves are significantly better than anything Senku’s made himself. Yet, at least. He’s fairly sure it won’t take much for Francois to have a bit of influence on their overall alcohol supply and adds it to the endless mental list of things he’ll be doing to improve his—everyone’s, really, but specifically his—quality of life.
In front of him, Senku huffs, lifting the hatch on the model’s miniature cargo hold. Raises his eyebrows in genuine intrigue, even as the rest of his expression stays largely unimpressed. It’s utterly fascinating.
“Are you happy, Senku?”
“You’ve been spending too much time with the Mentalist.” Senku rolls his eyes and doesn’t look up. “Stay on task.” He’s entirely focused, more than half an hour into inspecting it after Ryuusui’s explained his next set of modifications, and—left only to answer questions—Ryuusui’s simply decided to stir up answers of his own.
“Then give me one,” he replies.
Senku doesn’t even hesitate. “Either make me a figurehead or turn the whole thing into a shark,” he says, completely deadpan, as he detaches the hatch. “Does this go right down to the main storage? Let’s make it glass. Give the goats some sun so they don’t mutiny.”
And Ryuusui—blinks. Entirely derailed. And explodes with laughter, only holding his drink steady through the joy because he’s extremely talented.
Senku just lets Ryuusui giggle it out, already measuring the little piece on the table’s inlaid ruler, taking measurements, doing brilliant math in his brilliant head and making notes.
“We’ll do a shark because I’ve never owned one before,” Ryuusui says, final. “Where’s the ink—” Senku just slides it to him across the table, and Ryuusui, just as assured, sticks his fingers in it and gets to work painting the bow with a messy, sharp-toothed grin. He thinks of Senku’s chaos in the throes of doing something horrifically dangerous and decides the ship should look like she could kill someone. “It’s going to be perfect.”
“Probably not,” Senku replies, simply a statement of fact, “but it’ll certainly be awesome.”
”Ha! That’s the spirit!” He doesn’t need to turn to know Senku’s making some sort of face at him. “And if we do glass, we’ll need to section it like a proper window. And you never answered my question.”
“Yeah, yeah.” It’s completely sarcastic.
“That’s not an answer.”
Senku reaches over to return the hatch to its place and Ryuusui stills, just in time, so his masterpiece isn’t jostled mid-paint. “I’m having fun,” Senku says. Shrugs. Starts poking at the beams around the opening. “You certainly aren’t bored.”
“In the general sense, I manage well enough because I’m not in denial.” He likes the ship’s face—it does look vaguely evil. It’ll be completely ridiculous scaled up to size, as it should. “That’s also not an answer.”
“Well, neither am I.”
“Aren’t you? In denial, I mean.”
“No.”
Ryuusui has never been a coward, so he just barrels ahead, blunt. “His body’s in a freezer, Senku. Serial killers do that.“ He doesn’t think Senku’s answer to any of this will change his decision because it’s too late for that, but still—he has to know anyway.
And Senku doesn’t even flinch. Of course. “One corpse doesn’t make me a serial killer,” he says, writing in his notes again. Measuring. Writing. Barely giving Ryuusui the time of day now because they’ve changed topics.
“You admit he’s a corpse.”
“So?” Senku doesn’t actually sound surprised, and Ryuusui realizes, suddenly, that cryostasis might have been as much for Mirai’s—maybe Tsukasa’s—benefit as his own. More than, perhaps. A fantasy tilt to reality without really hiding the truth. “This isn’t a board room, so save your lectures for someone who cares.“ It doesn’t change the facts as they are, though.
Ryuusui pushes the ink back toward Senku and Senku dips his quill in the pot without even looking up. And Senku sketches, cleanly, the vague outline of a new segmented hatch on his parchment. And Ryuusui takes a long sip of wine. And it’s still just fine.
Outside the lab, life goes on, exactly the same and completely different.
“If you lose something and it never comes back, you learn to grow around the absence,” Ryuusui says. He thinks of his father and of his family and of—of the whole of it all, really. The concept of something like a normal home, considered once and discarded from the moment his mother shoved him, small and bundled and unwanted, into Francois’s arms. And then, of course, he thinks of Sai. “But if you lose something and there’s a little piece of it still stuck in the wound, you’ll want to pick at it. Forever.”
“Well, thank you for the lesson in first aid,” Senku shoots back, sarcastic. “Did they teach you that in MacEcon or Sailing for Nepo Babies 101?” Ryuusui can’t help but admire that he can keep up the conversation even while working with both hands and half his brain. “Lucky for us both, I’m in perfect health.”
He gives Senku an eyeroll for that one. “Debatable—I’ve seen you try to cross the beach carrying anything.” It earns him a glare, which feels like a step in the right direction.
“Don’t compare me to Taiju.”
“I’m not comparing you to Taiju. I’m comparing you to a normal human being.”
“Wasn’t under the impression you cared one millimeter for that, Captain.” Normal.
“Oh, I don’t,” Ryuusui replies, grin wolfish. “It’s mostly an observation. Scientists like those, don’t they?”
“Unbiased ones.”
“Scientists or observations?” Ryuusui ignores Senku’s scowl. “Your rhetoric’s terrible. Keep up.”
“Doesn’t need to be good—I’ve got a mentalist to do my talking, and I’m going to find a new shipwright if you keep this shit up.”
“No, you won’t,” Ryuusui laughs. “You think I’m biased?”
“Don’t think you’re capable of the opposite, frankly.”
“Well, now you’re just flirting with me.”
Senku hisses air out through his teeth and the line he’s drawing slips, just a little, off angle. “Oh, fuck off.”
It’s full of meanness, sure—just like most of Senku’s jabs—but there’s something essential missing from it, too. Like always. Not only in this—the tease—but in the way Senku talks about the astronauts (he’s heard the record again and again) or in the endless speculation around Why-Man’s motivation for killing them all or even in the look on Senku’s face those the nights Ryuusui’s climbed up to the cliffside cave to help instead of Mirai.
“You’re not really mad,” Ryuusui says, completely convinced now. “Or really not mad. Fundamentally.” Senku looks at him like he’s stupid. Ryuusui doesn’t let him. “You know exactly what I mean. Real anger. The same way you won’t do real joy.”
Still, he just waves Ryuusui off, dismissive. “If I get mad now,” he says, “I’d have to be mad about everything that’s ever happened in my life, and I don't think I’d ever stop.” Then he shrugs and Ryuusui looks at him and that’s all there is to it. “Tsukasa’s the perfect example—”
“Tsukasa’s the perfect example of most things,” Ryuusui replies without irony. Senku rolls his eyes.
“No shit,” he says. “Focus.” The agreement’s so frank Ryuusui almost misses it.
Really, the whole thing’s funny now more than it used to be because no, Ryuusui’s never actually met Tsukasa, just heard about him through the hundred stories told by everyone who’s ever encountered him and then some, the secondhand accounts of the people who’d fought his proxies, but Ryuusui would like to. Meet him someday, that is, if only to see all what all the fuss is about. Knows he will, whatever contingency plan Gen’s got in mind, because Senku’s decided Tsukasa is going to come back from the dead. And if the entire global population (as it stands) believes in his ability to do so—backs it, too, despite having sent their strongest to fight or fought or been loyal to him in the first place—Ryuusui is inclined to, too.
No shit.
And also, of course, because Senku has risen to every challenge Ryuusui’s presented—and presented his own in return with the same cocktail of sincerity and intrigue. So why would Senku not be the type to get whatever he wants, just the same as Ryuusui? And he wants Tsukasa. That much is clear.
“I am focused,” Ryuusui replies. “That’s the point, my alliumatic marvel.”
“Rejected. Go back to Dirac.”
“That one wasn’t bad. Shakespeare, eat your heart out—and all that.”
“I’m not questioning the linguistic logic, just telling you it sounds stupid.”
“Why? You should be proud—I’m settling for generalizations. You’re not sweet enough to be garlic but you haven’t made me cry yet, so I just have to give you the whole family.”
“Allium is the genus.”
“And you’re a genius.”
“Fuck off. Again.” Senku flips him the middle finger, thoroughly done with his shit. “I prefer the insults.” And then there is a shift, minute, away from the ridiculous. “You’re missing my point.”
“No, I understand the point fine,” Ryuusui replies, softer. He’s something close to serious because this is important to Senku in a way he knows but doesn’t welcome but will accept either way—accept because it’s important to Senku in the first place. “I’m simply stating the obvious. Call it another unbiased observation—and this one’s free.” Senku rolls his eyes. “Tsukasa’s ill-managed attempt at world domination was the natural consequence of anger left unchecked. Not felt.” And realizing something, Ryuusui raises one eyebrow, utterly baffled. “You’re not going to become a dictator if you feel one thing once, Senku.”
When Senku glances back, he’s just as thrown—like Ryuusui’s just suggested—well, Ryuusui isn’t actually sure, because he hadn’t been aware Senku could be surprised. It’s an interesting look on him.
“Of course I’m not going to become a dictator,” Senku says, completely put-out. “Do you have any idea how much work that would be? Where would I find the fucking time?” And Ryuusui blinks at him, and Senku just shakes his head—and Ryuusui realizes he might actually be on the verge of losing Senku’s full attention simply because he’d been wrong. He wants it back very badly. “I mean that anger’s unproductive. Generally. It clouds objectivity and cripples rational decision-making, and the hormonal response to feeling it in the first place is inherently addictive by virtue of the chemicals involved.”
Ryuusui raises one eyebrow. “True enough, I suppose.” Ryuusui gestures vaguely with his glass and goes to drink and realizes, suddenly, that it’s empty. Reaches for the bottle and refills it while Senku keeps talking.
“It’s why ragebait works—the more you feel it, the easier it is to feel.” Senku shrugs. “And because I’m uninterested in having my reasoning compromised, I’ve decided simply not to.”
“Broadly speaking.” It’s pointed.
“Well, yeah.” Senku huffs. “I’m only human.” And without looking he reaches over for Ryuusui’s glass, takes it, and drinks—already entirely focusing back on the model between them both. Ryuusui just lets him, fascinated. “But there’s a difference between rage and inconvenient upset. Rage comes from the belief that something is over. Unsalvageable. Final.” He carefully extracts one of the forebeams from the model and rests it on the table’s inlaid ruler, then—barely pausing—writes out a series of ever-increasing numbers in notes. Upscale calculations, all done in the beautiful wonder of his head. Then he twists the boom, the mainsail, fifteen perfect degrees starboard. “And I don’t believe any of that is true for anything.”
“You’re surprisingly philosophical for a man of science.” Ryuusui takes the wine back and drinks too. This pour’s better somehow. Deeper, richer, more interesting.
“Philosophy’s just logic, and that’s all science is, too.” Senku scoffs. “And I don’t enjoy science that lacks conversation—the exchange of ideas. The human element is what makes it worthwhile.”
“Like what we’re doing now.”
“Don’t sound so pleased about it.”
“I understand the sentiment, at the very least.”
“Of course you do,” Senku says. “You’re a businessman—that’s also just applied logic. The same principles tilted toward a different goal: personal gain over discovery and advancement.” There’s no judgment in his tone, only the plain statement of facts. “You can’t do any of that without other people.”
“Business can drive advancement,” Ryuusui retorts. With one cracked finger, he tilts the model to the side just slightly—finishing the heel of Senku’s starboard tack to a perfect match. It earns him a twitch at the corner of Senku’s mouth and he’ll take it. “Look at the balloon—the hemp that got us to the linen to the sky.”
“I’m not debating the ethics of capitalism with you,” Senku says. “Take it up with Tsukasa if you want—he’s the one with strong opinions about all that shit.”
And that brings them back to the beginning, doesn’t it? Tsukasa, Tsukasa, Tsukasa.
“What if you can’t bring him back?” He keeps the edge out of it for both their sakes and because, too, he’s genuinely curious. “Who will I debate then?”
“I can,” Senku says. “I have a theory and I’ve already tested it once—I just needs to know if it’s repeatable.”
“When you died,” Ryuusui frowns. “When he killed you.”
“It was temporary.” Senku rolls his eyes. “That’s the point. You of all people should understand that, shouldn’t you? I doubt you’ve ever listened to anyone tell you no in your entire life.”
And Ryuusui—would argue that he has, maybe, if not for the fact that Senku’s just as right as always. He hasn’t given up on Sai, after all, and he hasn’t given up on Senku either. The brother he’s loved from the day he was born and the only man who’s ever been anything close to his equal. The only two things in the world he’s ever wanted and been unable to have (untrue, untrue) and that he’ll never give up on because that would mean—
“Real rage is just admitting something’s gone for good. It’s about giving up hope, and if you do that you have to grieve,” Senku says, “and once you do that you never get to stop.” Slowly, deliberately, with all of his concentration Senku turns the tiny mechanism that moves the masts just so—shifts the secondary sails and the whole boat too in the perfect mimic of a wind change. Tack to heel to turn. Brilliant. “And I absolutely don’t have time for that, either.”
And it’s not just about Tsukasa, Ryuusui realizes—not even about Senku himself. It’s about everything they’ve lost, collectively. The scale of it all. Every single accumulated atom of human potential, iterated endlessly throughout history. That chain of hands holding hands all the way back to the stone age and beyond, to that first wet thing crawling from the sea onto dry land: proof of lives lived. Proof of minds that thought and bodies that worked and hearts that loved. Proof of existence, tethered not to any specific person but to creation itself, erased in a second and the slow march of four thousand years after.
No matter how many people they bring back (all of them, or as close to it as Senku can get, Ryuusui is sure) the rest won’t follow. Infrastructure and art and records of everything else; every reference point tying them all back to the past, pushing them onward to the future. Foundation in the truest sense.
Senku’s not sentimental about preserving the things he’s made—Ryuusui’s seen him dismantle his own inventions to create something new more than once. But. But. He’s never seen Senku try to destroy the things that came before him, either. If there’s a better way, he builds on top of what’s already there, whether that be the huts in the village or the social structure of it all.
Chrome’s told the story more than once, after all (and everyone else, too; they can’t resist talking about Senku, everyone but Senku himself) how he never seized them by force and competed for the title of Chief just like everyone else. Didn’t even want to win, just wanted the influence of the position by putting Chrome on the seat next to Ruri. Got it against his will and gave them heat in the winter and light in the dark like he wouldn’t have done that anyway.
You cannot love the world, Ryuusui thinks, without loving all of it, past and present and future. And Senku loves the world more than anyone else, Ryuusui’s sure. Believes in it, intrinsically, more than anyone ever has and anyone ever will.
Ryuusui’s not so noble—not by a thousand measures.
So he does the only thing he can: he throws his head back and laughs. Laughs long and loud, eyes closed and tears at the corners of his eyes. Laughs until there’s nothing left in his lungs but some clear, tacit understanding that he’s fucked for the rest of his life. Has to hold his hat down with one hand even as he presses the other to the bridge of his nose and nearly doubles over.
Whatever Senku sees in the whole thing doesn’t matter, because Ryuusui doesn’t care what Senku thinks—not really. It doesn’t matter, because Ryuusui has his respect and his trust and maybe his friendship, too.
So Ryuusui just feels it, the revelation that Senku’s something better than all of them and something infinitely more fragile for it, too. And Ryuusui knows someday he’s going to get real goddamn mad for not the first but one of the few times in his life—he’s going to give up on something—and when he does, it’s going to be on Senku’s behalf. Because Senku’s never going to do it himself, no matter how much whatever it is hurts. No matter what he finally loses for good.
The irony isn’t lost on Ryuusui, and that makes him laugh all the harder.
“Don’t break now,” Senku snorts, barely glancing up, impatient dismissal in the creases around his red-sky eyes. “You haven’t taken me around the world yet.”
Ryuusui grins back, wide and full of teeth. “You’re like a greedy little kid.” Senku just rolls his eyes.
“Takes one to know one.”
“And isn’t that fun?” Ryuusui certainly thinks it is. He’s never had so much fun, ever, not since the day he was born.
All Ryuusui wants to do is follow through and grab the sides of Senku's face and bite his neck and keep him there, Ryuusui’s forever, comfortable and happy and entertained. And, because Ryuusui’s never been one to want just one thing, he wants the opposite just as much—to let Senku go, set him free to do whatever he pleases, no matter what.
In the end he’ll do both, of course. Make himself a comfortable place at the center as Senku shapes the world, because the thing Ryuusui has always chased hardest (really, ultimately) is just the happiness of anyone he’s decided to—
Ryuusui grins against Senku’s skin and relishes the way the flat of his front teeth presses into the curve of his collarbone, gentle and savoring. Soft. Delights, wholeheartedly, in the physicality of Senku’s lean body and the miracle of everything it holds underneath muscle and sinew and promise, too. Says, “I love you,” because he means it with his whole everything, and Senku says—
“Well, get over it,” through a groan because he’s honest to the core.
It’s only natural, of course.
He wouldn’t be Senku at all if he were one millimeter capable of delicate heartbreak, and that’s more than half the reason Ryuusui loves him in the first place.
Fifteen years later—maybe more, some large chunk of which they’d both been frozen while Suika worked and worked and worked to save them all—the Perseus 4 tosses anchor in Treasure Island’s coastal waters and Sai wanders across the dock on shaky, seadog legs, and Francois disembarks behind him straight-backed and ageless, and Senku’s nowhere in sight.
It’s not unusual anymore.
There’d been a time when Senku welcomed every ship, excited about the cargo and maybe the people, too, but the more the people they’ve revived—the more of civilization Ryuusui himself has worked hard to rebuild—the faster the countdown on their mission has clicked. Sentimentality’s been shaved down to threads between them all in the face of the work, and half the reason he’d been allowed to take Sai away from his project in the first place had been so he could inspect Corn City’s work on the return rocket’s computer with his own two eyes. A necessary sacrifice.
And yet—when Ryuusui checks, Senku’s not in any of the lab facilities with Xeno and Suika, not in the machining district with Chrome and Kaseki, not even in the new village proper with Ruri and Mirai. Ryuusui would worry Senku’s set off for the mainland or (fuck forbid) been lost if not for the fact that no one’s let him out of their sight for more than half a second since he’d been sniped (the first time) a lifetime ago, whether they’d seen his body hit the deck or not.
So diligently, patiently, without pause, Ryuusui follows the chain of He’s with so-and-sos, and He went that ways until he finds himself climbing the hillside path to a cliff’s edge that might have been familiar once but looks so, so different now, after years of progress.
Senku’s there at the cape, sitting in the dirt in direct sunlight, surrounded by a dozen rods and flags and wires feeding a constant stream of meteorological data into the rudimentary readout at Senku’s side while he takes notes—does calculations somewhere in his head and adjusts the numbers on paper accordingly.
If Ryuusui closes his eyes, the instruments’ small propellers might sound like the wings of a little drone of wood and string and grit-toothed ingenuity—maybe, maybe, maybe.
He doesn’t dwell on it.
Amaryllis is there too, sitting in the shade of a nearby tree with weaving in her lap—because no matter how advanced their technology, there’s always work to be done. Ryuusui tips his hat to her. She smiles back, genuinely glad to see him, and though he hasn’t spent nearly as much time with her as the rest who’ve set down roots here at the launch site, he can’t help but marvel at how she’s grown even more beautiful with age and motherhood, the new master’s wife and queen of an island at peace.
And without looking up from his work, Senku drawls, “Figured you’d be back soon,” entirely apathetic, because no matter how many years have passed, so many things do still stay the same.
Ryuusui grins. “And I see that you’ve finally replaced me entirely—who needs a man who knows the weather when you’ve got science to do it for you?”
That does get Senku’s attention enough to earn him a glare, “Ha, ha,” without inflection, and Ryuusui just grins back. Keeps walking until he’s standing right over Senku, blocking out the sun so Senku has no choice but to look at him. Senku doesn’t take the easy bait—the wide open door to I’ll always need you that’s true and something he’ll never hear because what’s the point of stating the obvious. Senku looks at him like he’s stupid anyway.
It’s all Ryuusui wants, really.
So with all the drama of everything he’s ever done in his life, Ryuusui stretches his arms over his head, says, “Shit, I’m tired. Mooring’s hard work in a vessel that size, you know,” and gracelessly—like a dog with four left feet—flops on the ground next to Senku. The noise of dismay Senku makes is worth the impact and the way it flips his hat clean off. He laughs again, breathy.
“If you’re tired, go sleep in your hut,” Senku gripes, and this time when Ryuusui looks he has to squint against the brightness just to see Senku.
“Hmm,” Ryuusui hums, propping himself up on his elbows to grab at his hat, and says, “No,” like a child. He catches Senku’s eyeroll just enough to compliment the whole hassle and then—
Without warning, unable to help himself—Ryuusui shoves his hat onto Senku’s head. And before Senku’s even finished cursing him out, Ryuusui’s already put his head on Senku’s thigh—positioned perfectly so Senku’s blocking out the sun and he’s not entirely on the hard dirt anymore and there’s nothing else in the way of the view.
He grins.
Senku glares down, one hand halfway through tilting the hat out of his eyes and the other thrown back for balance, and he doesn’t shove Ryuusui off. Doesn’t even give the hat back, either. Just sighs a hiss through his teeth, mostly unamused, and says, “You’re a pain in the ass.”
“Oh, naturally,” Ryuusui laughs, and he turns his face up to the warmth of the afternoon.
“I’m doing shit and you’re in the way.”
Of course, Ryuusui doesn’t move—he has no intention of doing so, really. Just shrugs and crosses one ankle over the other and both hands on his chest, too. Settles in. “I desire company,” he says, like he hasn’t been on a cramped ship with two dozen sailors for the last however-many weeks.
“And I desire peace and quiet.”
“Then I’ll stay silent,” Ryuusui retorts, “and we both get what we want.”
And Senku looks down at him, something unreadable and beautiful and thinking in his expression, then huffs, “Fine. Whatever.” And Ryuusui knows he’s won, just for a moment. Long enough for Senku to turn back to the readouts in front of them. Long enough to return to that endless cascade of notes. Long enough for one hand, absently, to card through the greasy clumps of Ryuusui’s sea-sweat bangs in Senku’s constant need to be wholly occupied.
It’s plenty.
Senku mutters to himself and Ryuusui listens without processing a word he’s saying, most of it nonsense around the truth that Ryuusui is tired. Exhausted, entirely, in that way of a job well done; in that way of muscles allowed to relax after coming home, all ache and decompression.
It’s not a lie so much as a compromise so much as the only possible outcome from the very beginning, because really (really) Ryuusui is still getting what he wants—because what he wants (more than anything) is for Senku to get what he wants. And Ryuusui would, and has, and will continue to do whatever it takes to make that happen.
Fluorite and the greatest mathematician of their generation and a transcontinental labor force and the rest of the world—if you want it, I’ll get it for you. Will buy it or make it or find someone who can, just as he has forever, as far back as the Medusa and first day of the rest of his life. You wanted a way to save Tsukasa so I took you there. You want a way to the moon and I’ll take you there, too. Again and again, because that’s what captains do.
Here at the site of one end of the world (just a day, really, in the grand scheme of things—because they’ve all gone down in a spray of blood more than once since then and the world’s ended a few times at least) Ryuusui thinks—
I died for you (because if there’s logic to calling Tsukasa a mass-murder for breaking statues, Ryuusui throwing himself in front of Senku to be shattered is the same) and Tsukasa just died. Maybe you’d think of me differently if you’d killed me yourself.
Senku’s tongue is a pink slip stuck between his teeth as he squints down at the next section of numbers and scribbles something else and—
Ryuusui knows that isn’t how it works. Knows because that’s half the twist: he’d never try to kill Senku in the first place and never need to be killed for redemption in return—no matter the real reason—like the universe’s sick approximation of a closed narrative loop. Tsukasa feared him for the same things Ryuusui has always loved, after all, and still—still.
Still.
“We’ll need to call Tsukasa home soon, won’t we?” Ryuusui murmurs. “It’s almost time to decide who’s going up to space with us.” And the hand in Ryuusui’s hair stills, even as the rest of Senku doesn’t react.
“Oh, really?” Senku hums. “I hadn’t thought much about it—been too busy with other shit.” He draws a line there, in his notes, and it could mean anything. Scowls. Says, “Xeno’s a fucking handful to manage. I have no clue how Stan did it all those years,” without an ounce of self-awareness. He’s still wearing Ryuusui’s very favorite hat like he hasn’t even considered taking it off.
“Most geniuses are like that,” Ryuusui says, and Senku makes a face—looks at him again, finally, and Ryuusui looks back.
Neither of them call the other out on all the things left unsaid; Senku’s lie and Ryuusui’s truth. They don’t need to. They’ve done it all before.
Instead, Senku scoffs, “You’re not doing a great job at the whole quiet thing, you know,” and picks back up where he’s left off, the same as ever. “So much time in India you’ve forgotten how to speak Japanese?”
And Ryuusui just grins—closes his eyes—and laughs. “I’ll go get him for you, Senku,” he says. “As soon as I wake up, I’ll resupply and I’ll sail down to South America and I’ll bring back Tsukasa for you, I promise,” just like everything else. Just like always. Like that’s all there is to it.
Because that is it.
After a third (or more, maybe—half) of their conscious lives spent in orbit around one another, Ryuusui knows what Senku wants just as much as he knows himself. More than, even, in that way of beautiful loopholes found by people in love—and by people who’ve let their love wear down into a simpler, steadier friendship.
And he means it, too. All of it.
With his whole goddamn greedy heart, he really, really means it.
In the very beginning, four thousand years crumbles away and Ryuusui laughs—as he always has, always will, because the alternative isn’t an option—in the face of another challenge presented at his feet. The sun is half-risen and there’s sand under his bare feet and the rest of him’s naked, too—and the coastline is wrong. Shoved so far in for at least two kilometers into the west with no sign of the sheer underwater cliff that made this this the perfect island for a sailing academy, high depths closer than average to land, and—
The buildings are gone. The rest, too.
“Lucky for us, you catch on quick,” the man in front of the group says. He’s their leader without question, a strong spine hidden under his scrawny appearance, cycling through surprise then a smug, condescending delight at Ryuusui himself as Ryuusui talks.
Ryuusui’s used to derision as much as he’s used to arrogance, but there’s something different—glittering—in a pair of eyes the color of sailors take warning.
Senku's the one to revive Ryuusui, after all; a feat in and of itself. Even if he doesn’t have power, he has influence—except—of course he does. Have power, that is. All of it. And he’s utterly uninterested in doing anything with it but build a ship to save some freeze-dried asshole and then the whole world, too.
Ryuusui has to have him, immediately and without hesitation, because he knows if he doesn't (knows like he knows the sour, sticky feel of saltwater on his skin, of high-low pressure changes in his joints, of cool gold heavy in his hands) that Senku will take him instead—easily and just as quick. Forever.
Probably already has, whether either of them realize it or not.
And staring back, Ryuusui thinks—wouldn’t that be something? To experience being taken instead of doing the taking himself.
He can’t help but want it, of course—just a little, just like everything else.