Chapter Text
I: Departure
The train platform smelled like old coffee and damp concrete—familiar in a way that tugged something loose in his chest. Izuku adjusted the strap of his duffel bag, boots crunching softly against the gravel. The winter air bit at his fingers even through his gloves, sharp and insistent, like it wanted to wake him up from the fog in his head.
He hadn’t been home in almost four years.
University life had kept him busy—papers, labs, late-night study sessions in libraries that never seemed to sleep. He’d built something for himself there. Friends. Structure. A sense of forward motion. But underneath all that, there was still that persistent ache, a hum just beneath his skin. Like he’d left something behind he wasn’t supposed to.
Something unfinished.
The train hissed as it pulled into the station, sleek and silver against the gray sky. Izuku waited with the others, boarding pass in hand, shoulder-to-shoulder with strangers bound for destinations he’d never know. There was something poetic about that, he thought. People moving through each other’s lives in silence, sharing space for a moment, then disappearing again.
He stepped inside and found his car—Car 6, Seat B12. The cabin was warm, buzzing with quiet conversation, the hum of heaters, the occasional laugh. He moved down the aisle, trying not to make eye contact with anyone, fingers brushing the edge of each seat as he passed.
Then he saw him.
Katsuki.
Head tilted back against the window, headphones on, eyes half-lidded like he wasn’t fully awake. Or maybe like he didn’t care. He looked... older. Sharper. The kind of older that wasn’t just about years, but about weight. About time passed in silence.
His hair was still a mess of ash-blond spikes, but neater now, more intentional. His jaw was set like always, but there was something quieter in the tension now. Like it wasn’t about anger anymore, but control.
Izuku’s heart stuttered, caught between surprise and something that felt suspiciously like longing. He hadn’t even realized how much he’d missed the sound of that silence between them until it was here again, echoing in the narrow train car.
Seat B12 was just one seat away.
He slid into it without a word.
The seat next to Katsuki—B11—was empty, but it wouldn’t stay that way for long. He could feel Katsuki glance his way, just for a second, before looking out the window again. Not a word. Not a nod. But Izuku felt it. Like a static charge between them, old and familiar.
It was impossible not to. Katsuki sat with his legs stretched out in front of him, one arm slung carelessly over the armrest, his head tilted slightly against the window. Headphones rested snugly over his ears, and his eyes were closed—though Izuku couldn’t tell if he was actually asleep or just pretending to be.
He looked… different.
Older. Stronger. His jaw was more defined now, cheekbones sharp under the soft light, and his frame broader—his shoulders filling out his hoodie in a way that made Izuku’s breath catch for reasons he didn’t want to examine too closely. His hair was the same messy explosion of ash-blond, though slightly more tamed now, like he’d finally found a way to control the chaos. Or maybe just stopped caring as much.
But it was still him.
Undeniably him.
Izuku’s heart stuttered in his chest, skipping a beat like his body didn’t know how to process the collision of now and then. His grip on the strap of his bag tightened.
He thought about turning around. Just for a second. He could find another car. Ask for a seat change. But no, this was his assigned seat—B12—and he could already feel eyes behind him as people shuffled into the train, looking for theirs. He didn’t have the luxury of running away this time.
So he stepped forward.
Katsuki’s seat was B10. Izuku’s was B12. Close enough to feel the weight of the past between them. Not close enough to speak without making a conscious effort.
He slid into his seat as quietly as he could, careful not to make too much noise as he tucked his bag under the seat in front of him. The space around them seemed to contract, like the air itself had tightened. The hum of the train engine filled the silence—but it wasn’t enough to drown out the awareness crawling up his spine.
Izuku didn’t look at him. Not directly.
But he felt it—the flicker of eyes on him. A half-second glance. Katsuki had opened his eyes. Just barely. Enough to recognize him. Enough to see.
Izuku kept his gaze fixed on the back of the seat ahead, trying to pretend he hadn’t noticed.
Neither of them spoke.
The silence between them was thick—dense with everything left unsaid. Four years of it. Four years of growing up apart. Of wondering, of avoiding, of hurting. It stretched between them now like a live wire, humming, waiting for a spark.
Izuku shifted slightly in his seat, hands curling into his lap. His mouth felt dry.
Say something, a voice whispered. Just say something.
But he didn’t.
Because Kacchan hadn’t either.
And maybe that meant something.
He looked down at his hands, fiddled with the zipper on his coat, tried to steady his breathing.
He wanted to say hi. He really did.
But his throat felt tight. Like any word might collapse under the weight of four years of silence.
So he stared out the window instead, watched the world blur past as the train began to move. Away from the city. Toward home.
Toward everything they hadn’t said.
—
Izuku pressed his forehead lightly against the window, the glass cool against his skin. The city was already shrinking behind them—tall buildings softening into gray silhouettes, swallowed by the blur of passing trees and telephone wires. He let his eyes follow the scenery, but his mind kept circling back to the same place.
To Katsuki.
To the seat just one row away, where the silence felt louder than the steady hum of the train.
He hadn’t seen Katsuki since graduation. Not in person, not online. No updates. No posts. No passive-aggressive liking of old photos. Nothing. Like they’d both agreed to vanish from each other’s lives—but Izuku didn’t remember agreeing to that.
He didn’t remember much about the ending at all. Just the feeling of something cracking between them—something quiet, but deep.
One week they were still… something—walking home in silence, texting occasionally, passing each other notes in class under the pretense of study questions. And then suddenly… they weren’t. One unanswered message. Then another. Then none at all.
He wasn’t even sure who gave up first. Maybe it had always been destined to fall apart.
But that didn’t make it hurt less.
Izuku swallowed around the lump in his throat. His fingers curled slightly on his knee, the denim warm beneath his palm. His stomach had that soft, sick feeling it got whenever he was anxious—like he’d missed a step on a staircase and hadn’t landed yet.
He told himself it was fine. That they were different people now. That it had been years.
But a part of him—small, stubborn, still seventeen—wanted to turn around. To see if Katsuki was really asleep or just pretending. To whisper “Hey. You look different.” Or maybe “You haven’t changed at all.”
Instead, he stayed still. Eyes forward. Breathing slow.
Maybe Katsuki didn’t want to talk. Maybe he didn’t even remember the way their friendship collapsed like wet paper. Or maybe he did, and that was worse.
Still, Izuku couldn’t stop remembering.
The way Katsuki used to walk him halfway home even when he didn’t need to. The late-night texts—gruff and sarcastic, but always checking in. The day Katsuki sat next to him at the train station after his mom’s fight with him, saying nothing, just handing him a bottle of juice.
Moments that meant nothing. And everything.
He closed his eyes for a second and let the hum of the train settle into his bones.
They had hours left on this ride.
Hours with the ghost of what they used to be sitting just one row away.
—
The train rocked gently on its tracks, the rhythm steady and soothing in a way that made it easy for Izuku’s thoughts to drift. His eyes stayed fixed on the window, but the world outside blurred into memory.
High school.
Late afternoons with golden light filtering through classroom windows. The quiet shuffle of notebooks. The way Katsuki used to lean back in his chair during study halls, arms crossed, scowling at the ceiling like it had insulted him. He’d only offer help when Izuku was completely stuck—grumbling about how he was “too damn soft to survive finals” while scribbling out chemical equations in sharp, impatient strokes.
They weren’t friends, not really. Not in the way people expected. But they weren’t strangers either.
There were moments.
Moments when they lingered after class, walking down the street in the same direction even if neither admitted they were waiting for the other. Moments when Katsuki would send a late-night text—just a photo of his notes and a “You better pass, nerd,” attached. Moments when they sat beside each other during lunch, not talking much, but not needing to.
Moments when Izuku felt like maybe, maybe, they were slowly building something that couldn’t be named.
And then it broke.
He still didn’t know why.
One day, Katsuki just stopped replying. No more texts. No more quiet study sessions. No more walking together after school. Izuku asked once—hesitant, fumbling—but Katsuki brushed him off with something cold and sharp, and after that… he didn’t ask again.
He told himself Katsuki was just busy. That maybe it was just stress or exams or something stupid.
But deep down, he’d known.
Something had shattered. Quietly. Irrevocably.
And neither of them had the courage to try picking up the pieces.
——
Izuku blinked, breath catching just slightly as the train hit a turn. He looked down at his hands. They were trembling. Just barely.
He didn’t even know if Katsuki remembered those moments the way he did.
Maybe he was the only one still carrying them.
—
II: Stops along the way
Katsuki cracked open one eye.
Of all the goddamn people on this train.
He didn’t move. Didn’t take off his headphones. Didn’t even change the way he was slouched in his seat. But the second he saw that mop of messy green hair and the nervous shuffle of sneakers against the floor, something in his chest clenched—tight, instinctive, stupid.
Deku.
He hadn’t thought about him in months. At least, that’s what he told himself.
Now the past was sitting two seats down, awkward and silent, like a ghost he didn’t ask to be haunted by.
Katsuki let his eyes drift shut again, jaw tightening.
Izuku hadn’t changed that much. Still soft around the edges, still twitchy in that way that screamed overthinker. But there was something else now—shoulders a little straighter, the slouch a little less obvious. He looked… older. More sure of himself. A version of the kid Katsuki used to know, peeled forward in time.
And that should’ve been fine. Should’ve been nothing.
So why the hell was it still sitting in his chest like a weight?
Katsuki adjusted his headphones, but he didn’t press play again. Just let the silence settle around them like dust.
He wasn’t going to say anything. This wasn’t anything. Just bad luck. Assigned seats. Random chance. Whatever. The universe liked pulling shit like this. Didn’t mean he had to entertain it.
He was here to go home. That was it.
Go home, see his mom, eat some actual food, and try not to think about how fucking weird it felt being back after so long.
He wasn’t here to deal with old wounds and green-haired ghosts.
But still.
He could feel Izuku’s presence like a static charge—like something waiting to spark.
And it pissed him off how aware of it he was.
Like some part of him had been waiting for this.
Goddammit.
—
The train rumbled on, steady and slow, cutting through long stretches of countryside that blurred past the windows in streaks of green and gold. Every so often, the wheels hit a rough patch on the tracks, rattling just enough to jostle Katsuki’s arm off the armrest.
He flexed his fingers, cracked his knuckles, and focused on not looking left.
Because he could feel it.
That damn glance.
Again.
Midoriya was trying to be subtle about it—eyes flicking over like he was just checking the time or looking out the window. But Katsuki knew better. He knew what it looked like when someone was carrying unsaid shit in their eyes. Especially his unsaid shit.
It was the fifth time. Maybe the sixth. Katsuki had stopped counting after three.
He kept his eyes locked forward, arms crossed now, chin tilted up like he didn’t even notice. Like his pulse hadn’t jumped the first time Izuku sat down and he caught a glimpse of his face up close—older, yeah, but still so familiar it stung.
He hated that.
Hated how easy it was to remember how Izuku used to look at him—like he wanted to understand every sharp edge Katsuki refused to let him near.
And now here they were.
Ten feet apart. Practically strangers. Except for the part where Katsuki knew the way Izuku tapped his thumb when he was overthinking. Which he was doing now.
Tap. Tap. Tap.
He gritted his teeth and stared hard at the passing trees.
The train made a stop—some small-town station Katsuki didn’t bother to register. A few people got off. A few more climbed on. The doors hissed, the conductor’s voice crackled overhead, and still, neither of them moved. Neither of them spoke.
It was like they were playing a game of who could out-silence the other.
And for once, Katsuki wasn’t sure he was winning.
Another thirty minutes passed. Another stop. Another round of that stupid tap tap tap on the fabric of Izuku’s jeans.
Katsuki swore under his breath and shifted in his seat, just enough to lean against the window again, angling his body slightly away. Not because he was bothered. No. Of course not.
It wasn’t because Izuku’s presence was starting to crawl under his skin like a phantom itch he couldn’t reach.
It wasn’t because he kept catching himself remembering things he’d buried for a reason.
Like the time they skipped class and sat on the rooftop, neither saying much, but not needing to. Or the night before graduation, when Katsuki almost said something—almost—but swallowed it back and let the silence take it instead.
His jaw clenched.
This wasn’t the time. Wasn’t the place.
But goddamn if the silence between them didn’t feel loud.
Like something was trying to come alive again.
—
It was somewhere between the fourth and fifth stop that the silence started to grate on Katsuki more than he was willing to tolerate.
Not because he had anything to say.
Not because he cared.
Definitely not because Izuku kept fidgeting, tapping his foot or adjusting the strap of his backpack like he was trying to keep busy so he didn’t implode from whatever awkward tension was hanging between them.
No.
It was just—annoying. That’s all.
Katsuki sighed, low and sharp through his nose, and leaned forward a little, elbows on his knees. He didn’t look at him when he said it. Didn’t need to.
“You still gonna be a damn nerd forever, or what?”
The words landed with the kind of weight only years of silence could give them.
Izuku blinked. For a second, he didn’t react—like he was making sure he’d actually heard it right. Then his mouth twitched. A laugh—not quite full, more like a puff of air, surprised and warm—escaped before he could stop it.
It filled the space between them like sunlight cracking through fog.
Katsuki resisted the urge to smirk.
Izuku rubbed the back of his neck. “I mean… yeah, probably,” he said, voice a little hoarse but still bright. “It’s kind of a lifelong affliction at this point.”
Katsuki snorted, the edge of a grin tugging at the corner of his mouth before he could catch it.
“Figures.”
They both went quiet again—but it wasn’t the same kind of silence. It wasn’t heavy anymore. Not sharp-edged and suffocating. Just… tentative. Waiting.
Izuku glanced over, and this time, Katsuki didn’t look away.
He held his gaze for a beat longer than necessary, then shifted back to the window.
Not quite a truce.
But maybe a crack in the wall.
—
The hum of the train filled the silence that followed, soft and steady, like it was listening in.
Izuku turned slightly in his seat, one leg tucked under the other. “So… you’re heading back for break?”
Katsuki shrugged. “Yeah. Haven’t been back in a while.”
He could feel Izuku’s gaze lingering, hesitant but curious. “How long’s it been?”
“Almost three years.” His eyes flicked out the window, watching trees blur past. “You?”
“Same,” Izuku said quietly. “Feels weird, huh?”
Katsuki made a low sound in his throat, something between agreement and indifference. “Feels like stepping into a damn time capsule.”
Izuku chuckled again, softer this time. “Yeah. Like nothing’s changed, but everything has.”
They lapsed into silence again, but it felt different now—looser at the edges.
“So,” Izuku said, after a beat, “what are you studying?”
Katsuki hesitated. He wasn’t used to talking about it. Most people just nodded and smiled when he told them, like they didn’t expect anything less from him.
“Chemical engineering,” he said finally.
Izuku’s brows lifted, just a bit. “Oh wow. That’s… actually kind of perfect for you.”
Katsuki raised an eyebrow. “Yeah?”
“Yeah,” Izuku said, voice a little brighter now. “You always liked blowing things up in science class. Just—more controlled now, I guess.”
A smirk tugged at Katsuki’s mouth before he could stop it. “Controlled chaos.”
“Exactly,” Izuku said, smiling. And then, a little quieter, “That’s really cool, Kacchan.”
Katsuki felt something shift at the use of that name. He didn’t comment on it—just nodded, eyes back on the window.
“What about you?” he asked after a moment. “Still want to save the world?”
Izuku laughed, but it came with a tinge of self-consciousness. “Kind of? I’m doing a double major—psychology and environmental science.”
“Huh.”
“Yeah. I figured if I couldn’t punch villains, I could at least help people figure themselves out. Or help the planet not fall apart. Whichever needs more saving.”
Katsuki gave a low whistle. “That’s a lot of school.”
Izuku shrugged. “I like learning. And… I don’t know. I wanted to understand people better. Myself, too, I guess.”
The words hung there for a moment, and Katsuki caught the undertone. There was always something beneath Izuku’s sentences—layers he didn’t always show on the surface.
“Trying to explain why people do the shit they do?” Katsuki said, his voice quieter than usual.
Izuku’s eyes met his. “Maybe.”
Katsuki nodded slowly, fingers drumming once against his knee. “Sounds hard.”
“It is,” Izuku said. “But it’s worth it. I think.”
There was a pause, full and thoughtful, like they were both remembering a time when understanding each other felt like trying to solve an equation with half the numbers missing.
“Guess you always were the type to try and fix shit,” Katsuki said eventually.
Izuku smiled, a little crooked. “Yeah. And you always tried to blow it up and start over.”
Katsuki snorted. “Still do.”
They looked at each other again—really looked. There was something unspoken in the air now. Something old, but not unwelcome. Not anymore.
Izuku leaned back in his seat, eyes on the ceiling for a second like he was searching for stars that weren’t there. “I used to wonder what you’d end up doing. I always thought… whatever it was, you’d be good at it.”
Katsuki didn’t answer right away.
Instead, he leaned forward, arms resting on his thighs again.
“I didn’t think about you at all,” he said flatly. Then, quieter: “At first.”
Izuku turned toward him, surprise flickering across his face.
“But then I’d hear some lecture about heat reactions or combustion efficiency and—” Katsuki exhaled, like the words were getting dragged out of him. “I’d think, ‘Deku would go off about this for twenty minutes straight if he heard it.’”
Izuku laughed—this time, a real one. It was soft and familiar and damn near dangerous.
Katsuki looked away.
“Guess we’re both predictable,” Izuku said, his voice almost wistful.
“Guess so.”
The train rolled on, carrying them through old towns and older memories, and the silence that followed wasn’t tense anymore.
It felt like the kind of quiet that comes after a door creaks open—just a little.
Enough to let the light in.
—
Their laughter faded into a quieter rhythm. Izuku rested his cheek against the window, watching power lines whip past under the soft orange wash of late afternoon. His breath fogged up the glass, and for a while, neither of them spoke.
Katsuki didn’t need to look to know Izuku was lost in thought.
He could feel it.
“I used to think,” Izuku said suddenly, voice hushed like he didn’t mean to say it out loud, “that if I just held on a little longer, you’d stop pulling away.”
The words settled between them with too much familiarity.
Katsuki’s jaw tightened. His fingers twitched once on his knee.
“You always did that,” Izuku continued, still facing the window. “Back then. Pulled away right when it started to matter.”
Katsuki didn’t answer—not yet. His eyes were locked on the passing scenery, but his mind was trailing backward, unwillingly.
—
Second year. 20XX.
It was raining—of course it was. They stood on the rooftop after school, both soaked, neither moving to leave.
Katsuki remembers the way Izuku’s hoodie clung to his arms, heavy with rainwater, but he hadn’t complained. He never did, not when it came to him.
“You don’t have to pretend,” Katsuki had snapped, the words sharper than they needed to be. “I don’t need you hanging around like I’m gonna break.”
“I’m not pretending,” Izuku had said, quietly. “I’m here because I want to be.”
But that only made it worse—because Katsuki wanted it too. Wanted him there. Wanted the quiet way Izuku listened, the way he laughed at his dumb sarcasm, the way things felt right for a moment before Katsuki remembered he didn’t know how to be good at keeping people.
So he walked away that day. Left Izuku on the rooftop without looking back.
He didn’t return the texts that followed.
—
Third Year. 20XX.
A school festival. Katsuki had been volunteering reluctantly at a booth when he saw Izuku with someone else—laughing, leaning in close, the kind of easy closeness he used to share with him.
It shouldn’t have hit so hard. They hadn’t really spoken in months by then.
But it did.
So when Izuku caught his eye and smiled—tentative, hopeful—Katsuki had looked right past him. As if he hadn’t seen anything at all.
Izuku didn’t try again after that.
——
Back in the present, Katsuki exhaled slowly. His voice was quieter when he spoke, like something raw underneath the gravel.
“I didn’t know how to keep people,” he said, not really looking at Izuku. “I still don’t.”
Izuku’s gaze slid from the window to Katsuki’s profile. He looked older now—less sharp around the eyes, but more worn. Like someone who’d been carrying the weight of unsaid things too long.
“I let people hurt me,” Izuku admitted, just as soft. “I thought if I was patient enough, it would make them stay.”
They didn’t look at each other, but they didn’t have to.
“I guess,” Izuku said, almost with a smile, “we made a really great pair.”
Katsuki huffed out a breath—something between a scoff and a sigh.
“Fucking disaster, more like.”
And still, neither of them moved away.
The train rumbled on beneath them, a steady rhythm, like a heartbeat trying to hold it all together.
•••
Izuku watched Katsuki out of the corner of his eye, the tension in his shoulders softened now, but not entirely gone. The silence between them wasn’t cold anymore—just quiet, like an old sweater pulled from a box in the attic. Familiar. A little frayed around the edges.
His thoughts wandered, uninvited, back to those nights in their second year—the ones no one else really knew about. The nights Katsuki would throw a pebble at his bedroom window like they were kids in a story, and they’d sneak out under the pretense of needing air, or space, or just to escape the pressure building in their chests.
They never talked about anything big during those moments. Not directly. Just sat near the old vending machine behind the school, their shoulders barely brushing. Izuku used to imagine they were orbiting something fragile—something almost real.
There was one night he remembered clearer than the rest.
They’d talked about futures then. About how everyone expected so much of them, how none of it felt like theirs.
“I don’t want to be someone people just look at,” Katsuki had muttered that night, head tipped back against the metal wall behind them. “I wanna be someone that—someone that means something.”
Izuku had turned toward him, heart loud in his chest, and whispered, “You already do.”
Katsuki hadn’t said anything to that.
Just stared straight ahead like the words had landed somewhere too deep to touch.
And then, little by little, those nights stopped.
Izuku wonders now, watching the faint lines of tiredness at the corner of Katsuki’s eyes, if he remembers too. If he ever lies awake some nights and thinks about vending machine lights and half-finished confessions left to rust in the dark.
He wonders if Katsuki ever regrets it. The silence. The walking away.
Izuku doesn’t ask.
But his fingers twitch in his lap, aching to reach across the space between them—to ask somehow, anyhow—if any of it had meant what he thought it did.
The train rattled onward.
And for now, the question stayed between them, unspoken and heavy.