Archive of Our Own ^beta

Chapter Text

It doesn’t take a rocket scientist to know something’s wrong with Donnie.

Seriously, he claims to be mysterious and closed-off, but he’s an open book. The most “private” he’s ever been could more accurately be described as reclusive.

Lately, he’s been skipping meals, hiding out in his room or lab, and muttering to himself all night. He’s barely been going on missions anymore, choosing to stay behind, saying nothing.

We can handle things without him, sure, but it’s still weird. Especially coming from the same guy who usually won’t shut up about why he’d rather spend time with his screwdrivers than with us.

What’s even weirder? How often he’s been wearing clothes.

Donnie hates certain textures—can’t even stand most fabric—and now he’s dressing like it’s a second shell? It feels wrong. Like a crime against nature.

I didn’t think much of it when Raph and Mikey started wearing more too—they said it was to blend in with humans, which made sense. But Donnie? This isn’t about blending in. This is about hiding.

Maybe I’m overthinking it. He did come out to dinner earlier this week. He’s joined a few missions lately…

Still.

I rolled over in bed, scratching at my arm and neck, just trying to get comfortable enough to sleep. But then a cool sensation hit my skin and I jolted upright.

I turned on the lamp and sat on the floor, watching the ink crawl across my arm like always.

Just scribbles. The usual math equations, nerdy shopping lists. Nothing new. Nothing dramatic.

I first heard about soulmates when I was five.

Dad told us stories about people who were bonded so tightly they could feel each other’s pain or see drawings on their own skin from the other's pen.

Back then, I used to try everything to get mine to respond. Writing “hi,” drawing turtles, even dumb jokes.

But I got older. The stories faded. So did the hope.

Then, after my 18th birthday, it happened.

A cold tip dragging across my arm out of nowhere. A message. No, a list. Words and numbers. Nothing personal. No hello or acknowledgement that there might be someone else receiving these words.

Just ink. Just presence.

I didn’t write back. I didn’t want to scare them off.

I just… watched.

Now, five months later, I still haven’t written a thing.

But I’ve memorized the way the ink moves.

I’ve traced every word long after the pen stopped.

Tonight’s no different.

The clock near my bed beeped a few times. 3 a.m.

Typical. Insomnia’s a bitch.

I rubbed at the new marks, ghosting my fingers along the path the pen had taken.

Not my pen. Theirs.

I didn’t understand any of the equations scrawled across my scales.

Didn’t matter.

I stretched, back cracking, muscles aching from sitting hunched too long.

Still watching.

The ink stopped moving.

Sleep wasn’t happening tonight. Again.

I sighed and pushed myself up, walking down the dark hallway and padding into the kitchen. The lights hummed on low, casting long shadows across the tile.

Coffee sounded good. Not because I needed it—I was already too awake—but the routine helped. Something warm. Something still.

Filter. Grounds. Button. Wait.

I leaned against the counter, the cool air brushing across my arms. Ink still visible. I hadn’t bothered to cover it up.

Didn’t think to. Why did I suddenly feel nervous?

Footsteps approached—soft, careful. I didn’t look up. Just poured my mug.

“You’re up late,” came Donnie’s voice–quiet, scratchy, probably hasn't spoken to anyone in hours.

“So are you,” I said, sipping.

He stepped into view, dressed in one of his ridiculous layered outfits again—hoodie over long sleeves, socks even though he hated them. It was weird, seeing him bundled up, especially in the middle of July.

He moved to the fridge, opened it, stared inside longer than necessary. Grabbed something small—one of Mikey’s rice balls, I think.

I glanced over. “You still pretending you like those?”

“They’re convenient,” he muttered, not looking at me.

He didn’t sit down right away. Just stood near the fridge, chewing, watching me.

Or, more specifically, my arms.

It took me a second to register it. His eyes kept drifting—quick glances toward the scrawled numbers and half-written formulas still drying on my forearms. He blinked, looked away, then back again.

I stretched, oblivious. “You still working on whatever made this mess?” I motioned vaguely at my arm. I had confronted him before about the words and formulas, seeing if he could figure out who my soulmate is. He didn't seem to care much when I had asked him before.

Donnie’s lips quirked up. Not a smile exactly. More like… a sigh in the shape of one.

“Yeah,” he said. “Still working on it.”

“Sounds important.”

He hummed. “Depends who’s reading.”

I poured another half cup of coffee. “Hope they’re a genius, ‘cause I haven’t understood a single thing since it started showing up.”

“Maybe you’re not supposed to understand it,” he said.

I snorted. “Great. My soulmate’s cryptic and bad at labeling things. Sounds about right.”

He went quiet again.

But I could feel him watching. Not the coffee. Not the room.

Me.

I didn’t think much of it. Figured he was just spacing out.

“You should sleep,” I said. “You look exhausted.”

“So do you.”

“Fair,” I shrugged, sipping again.

Donnie finally sat down at the table. Hoodie sleeves tugged low, rice ball practically untouched. His fingers drummed absently on the wood, like he was building up to something.

But he didn’t say anything.

And I didn’t ask.

The silence wasn’t uncomfortable. Not really.

Just… full. Heavy in a way I couldn’t name.

His fingers were tapping out a rhythm against the tabletop. I knew that one. He used it when his brain was spinning faster than his mouth could keep up.

I didn’t say anything. Just let him think.

The ink on my arms caught my eye—still bold and black under the warm kitchen light. The formulas, notes, and weird shorthand spilled across my skin like a second language I’d never learned. I rubbed at one of the lines absently, not expecting it to go anywhere. It never did.

Not unless they erased it.

And they rarely ever did.

“You know,” I said, “whoever this person is—they’re kind of intense.”

Donnie’s eyes lifted toward me, quiet and unreadable.

I gestured at my arm. “Like, they’re not even pretending to be casual. It’s all just numbers. Codes. Nerdy grocery lists. Zero personality.”

His mouth twitched, but he didn’t speak.

“I mean,” I went on, half-smiling, “would it kill them to doodle a smiley face? Or say hi?”

Donnie blinked once, slow. “Maybe they didn’t think you’d want that.”

“Why wouldn’t I?” I asked, genuinely.

He looked down then, toward my arms. Toward the writing my soulmate left there hours ago. Maybe days. Some of it overlapped old notes from last week. I never washed it off. Couldn’t. Not unless they did.

“You used to write on yourself, didn’t you?” he asked suddenly.

“Yeah,” I said, a little surprised he remembered. “When we were kids. I’d write stuff all the time. Jokes, questions, even dumb drawings. Thought maybe they’d answer.”

Donnie’s voice dropped. “But they didn’t.”

I shook my head. “Not until after I turned eighteen.”

He nodded, like he already knew.

And something in his posture shifted—shoulders tense, hands still. His gaze flicked to my forearm again. I was still rubbing at the ink without thinking, like I could make it fade.

“You know it won’t come off, right?” he said softly.

“I know,” I murmured. “Just a habit.”

 A beat of silence went by. Not necessarily comfortable, but not unwanted either.

“You should try sleeping again,” he said, already standing. “You’re gonna crash if you don’t.”

I frowned. “I’ve had coffee. I’ll be up for hours.”

He hesitated at the doorway, like he might say something else. I waited.

Finally, without turning, he said:

“They probably don’t think you’re talking to no one.”

And just like that, he was gone.

Leaving me in the quiet with his words still fresh on my skin.

And the creeping feeling that maybe—just maybe—I was missing something obvious.

-

Chapter Text

9:07 a.m.

Leo had been lying on the couch for the past three hours, staring at his forearms like they might start talking back.

They didn’t.

Of course they didn’t.

But the ink was still there—unchanged, unrubbed, unmoved. The messy scrawl of equations, parts lists, schematics… all spiderwebbed across his arms like tattoos. Some fresh. Some older. Some written over themselves, the way someone might do when they’re anxious. Or maybe when they don’t want you to see what was underneath.

He tilted his wrist to look closer at a string of text near his elbow.

At first, it looked like nonsense—numbers, slashes, a note about copper wiring. But the way it bent slightly around a mole on his skin… the fact that the writer clearly knew the placement…

Leo exhaled slowly. “No way.”

"Yo!" Mikey’s voice blasted through the lair, followed by a dull thunk. “We got a mission alert, baby!”

Leo blinked, sitting up too fast and knocking over his now-cold mug of coffee. “What?”

“Check your shellphone,” Raph grunted, walking past with his gear half on. “Foot Clan’s pulling their usual garbage.”

Leo reached for his device, still dazed. One glance at the alert told him everything:

\[Urgent: Possible Foot Clan Activity – Report of theft from Midtown OfficeMax]

(Stolen: Paper. Again.)

“Oh my god,” Leo groaned, dragging a hand down his face. “We’re really doing this again?”

“Apparently,” Donnie’s voice came from behind, dry as desert sand. “What’s next, ink cartridges? Staplers? The scourge of modern office supplies?”

Leo turned to look at him. Donnie was already suited up, goggles slung around his neck, sleeves pulled down to the wrists again.

“Did you even sleep?” Leo asked.

“Did you?” Donnie shot back, but it wasn’t mean. More like a mirror.

Leo looked down at his arms again.

“…Not really.”

Donnie followed his gaze for a moment too long, then shifted his weight and looked away. “We’ll make it quick. In and out.”

Leo stood, pulling on his gear and glancing again at the writing.

Still there. Still untouched. Still…

…Something.

“Come on,” Raph called from the exit tunnel. “Foot ain't gonna stop themselves.”

Leo snorted and followed.

But even as they launched into the sewers, racing toward the city, he couldn’t stop looking down at his arms.

Wondering who, exactly, had left so much of themselves there.

-

Wind whipped Leo's mask tails around, making it hard to focus on the scene below. Again, he hasn't thought about covering up his arms, but why should he? Nobody noticed except for Donnie, so it didn't really matter. 

“What are they even stealing paper for? More origami soldiers?” Leo had one hand on his odachi, his other hand on his hip. He was about ready to just teleport into the building and slice all of the paper into confetti. 

“Seems like they're stealing more than just the paper.. the big guy is trying to haul a shredder out the door.” Mikey pointed towards the action, everyone's heads turning. Raph seemed heavily unpleased, and Donnie was barely registering a single thing. 

“Okay team, it’s another simple robbery. In and out. Are we ready?”

“Born ready!” Mikey chirped, already bouncing on the balls of his feet.

Raph cracked his knuckles with a scowl. “Can’t believe I’m sayin’ this, but I kinda miss when the Foot were at least trying to be threatening.”

Donnie said nothing. His gaze flicked to Leo—specifically, to the exposed arms marked in his own tight, chaotic handwriting. A formula near Leo’s elbow. A to-do list wrapping around his forearm. A note—half-erased but still visible—that simply read:

“Don’t forget to eat. Seriously.”

He remembered writing that. A week ago, maybe two.

Donnie’s grip on his staff tightened.

Leo, blissfully unaware, turned toward him and grinned. “You good, Dee? You’ve got that ‘I just calculated the heat death of the universe’ face again.”

Donnie blinked, his brain short-circuiting for a second. “I—I’m fine. Focused.”

“Cool,” Leo said, unsheathing his odachi. “Let’s end this paper chase.”

In a flash of blue light, he teleported into the building, vanishing from view.

Mikey whooped and dove in after him, followed by a grumbling Raph.

Donnie hesitated. He stared at the place where Leo had been a moment ago.

His handwriting was all over Leo’s skin.

And Leo still hadn’t covered it.

Did he not care?

Or did he really not know?

Donnie exhaled hard through his nose and followed them in, heart pounding faster than he wanted to admit.

Leo hit the ground running, blades drawn, landing between two rows of busted office chairs and a tipped-over paper display.

An origami ninja folded itself out of a legal pad right in front of him.

“You’ve got to be kidding me.”

It lunged. Leo sliced.

Shredded paper fluttered in the air like violent confetti.

“Leo, left!” Donnie’s voice shouted through comms. A paper shredder came flying at him. Leo pivoted and kicked it midair, sending it crashing into a discount printer bin.

“Are they animating the paper now?” Leo asked, dodging a flying envelope. “Why is this our life?”

“They’re using the leftover magic seals from that yokai incident last fall,” Donnie called, dropping down beside him and jabbing his bo staff through another origami warrior. “It’s temporary animation, incredibly inefficient—honestly almost impressive how stupid this is.”

One of the origami ninjas tried to backflip. Failed. Crumpled itself in shame.

Leo snorted. “That one’s trying to respawn.”

“Not on my watch.” Mikey launched himself from a desk and body-slammed it, popping back up with a fistful of googly eyes. “I am the chaos now!”

Raph grunted, dragging two unconscious Foot grunts by their collars. “One of these morons just tried to bite me. Through his mask.”

“That’s protein bonding trauma,” Donnie muttered.

“What?”

“Nothing.”

Leo twisted around to parry another ninja—this one made of copy paper and threatening him with a letter opener. He swiped down, cleaving through it in one smooth motion.

He didn’t notice the ink on his arm shifting as his muscles moved—how one of Donnie’s equations wrapped itself around his forearm perfectly, like it had been written *for* him.

Donnie noticed.

Donnie absolutely noticed.

He froze for just a second too long.

“You okay?” Leo asked, panting slightly. “You spaced out.”

Donnie forced himself to blink. “Yeah. Fine. Just processing how close I came to being paper-cut to death.”

Leo laughed, all easy confidence and oblivious sunshine. “Would’ve been a really stupid way to go.”

Donnie smiled tightly. “Yeah.”

Chapter Text

They had all gone back to the lair after the foot soldiers had gotten away, much to their distaste. It wasn't a total failure of a mission however. Those foot ninjas never got their paper shredder, and didn't get as much paper as they nearly had planned to steal. 

“I’m just saying,” Leo said, flopping dramatically onto the couch, “that origami ninja had *moves*. Like, I think I saw it do a tornado kick.”

“Because I programmed one to do that last year,” Donnie said automatically, “but that one didn’t have the proper balance ratio. You saw how it folded in on itself? Sloppy work.”

“How do you even program a piece of paper to do anything?” Leo snorted, scratching at his arm haphazardly.

“Are you critiquing the Foot Clan’s origami techniques?” Raph asked from the kitchen, shoving half a protein bar into his mouth.

Donnie blinked. “Yes?”

Raph grunted. “You need a hobby.”

“I have several,” Donnie said, adjusting his goggles.

Across the room, Mikey narrowed his eyes. He was half-hanging off the back of the couch, lazily spinning a fidget toy and watching Donnie the way a cat watches a laser pointer.

“Okay,” Mikey said slowly, drawing out the word like he was testing the flavor of it. “You’re acting weird.”

Donnie didn’t look up from his tablet. “I’m always weird.”

“Weird-er,” Mikey clarified, letting himself drop fully onto the couch now, chin on the armrest, eyes locked on Donnie. “Like… shifty. Like you’ve got a secret and it’s eating you alive. Which, if you do, I fully respect your right to be mysterious—unless that secret is about your health, the Foot, or a secret soulmate situation, in which case I absolutely have clearance.”

Donnie’s eye twitched.

Leo, meanwhile, was still scratching at his arm absentmindedly. Ink scrawled all across his forearm and wrapped around his elbow, he hadn't noticed it before but it was now slightly smudged. Has something happened to his soulmate? 

Mikey caught it. Narrowed his eyes.

“Hey, Leo,” he said casually. “Are you still seeing those random scribbles?”

Leo yawned. “Yeah, still showing up. You’d think they’d get bored of writing to themselves by now, but nah. Bunch of math and tech junk. I think I’m soul-linked to a walking calculator.”

Mikey’s eyebrows climbed his forehead. “Do you read it?”

Leo shrugged. “Eh. Sometimes. Half of it’s just lists and the other half I don’t understand. Pretty sure I learned more just by glancing at it than if I ever would have gone to highschool though.”

Mikey turned back to Donnie, very, very slowly.

Donnie was already staring at the floor, face carefully blank.

“Oh my god,” Mikey mouthed at him silently.

Donnie glared and shook his head once, sharply.

Mikey mouthed it again—“OH MY GOD.”

Donnie mouthed back—“I will disable your kneecaps.”

Mikey, undeterred, vibrated with barely restrained glee. Leo continued talking, entirely unaware of the silent conversation happening behind his back.

“I mean, I kinda wanted to write something back once, but it felt weird, y’know? Like, what if they think I’m creepy or something?” He paused. “Though, they did write ‘Don’t forget to eat, seriously’ once. So maybe they’re just a really aggressive nutritionist.”

Donnie visibly cringed.

Mikey’s eyes sparkled with unholy delight.

Raph finally emerged from the kitchen and flopped into a chair. “What’s goin’ on?”

Mikey opened his mouth.

Donnie launched a pillow at him.

He didn’t say a word.

He just stood up, tablet tucked stiffly under his arm, and walked out of the room with the mechanical precision of someone either about to explode or sob into a pile of spare wires. The only sound he made was the click of his bedroom door shutting behind him.

Leo blinked after him.

“…Did I say something weird?” he asked.

“Nope,” Mikey said, way too quickly, with a beatific smile.

Raph raised an eyebrow. “Then why you smilin’ like that.”

Mikey scooted closer to him on the couch, cupped a hand to his mouth, and whispered like a six-year-old at a sleepover:

“Donnie’s soulmate is Leo.”

Raph stared at him.

“What.”

“I know,” Mikey hissed. “It’s like—boom. All the signs. The tech scribbles, the guilt-tripping hydration reminders, the way Donnie keeps glitching whenever Leo stretches and accidentally shows his arms. The math is mathing, Raph.”

Raph looked at Mikey, then at the doorway Donnie had left through, then at Leo—who was stretching his arms above his head and yawning like a cat.

“Leo,” Raph said flatly. “You good?”

Leo blinked, mid-yawn. “M’fine. Just… tired, I guess. Gonna head to my room for a bit.”

Mikey waved. “Sweet dreams, ink boy.”

“Thanks?” Leo said, completely baffled, before disappearing down the hall.

---

The quiet of his room was a sharp contrast to the chaos of the main living area. Leo flopped face-first onto his bed, then rolled over and stared at the ceiling.

His arms were still marked with the remnants of Donnie’s earlier scribbles. Diagrams, formulas, a few to-do list items that made no sense unless you were already halfway through building a particle accelerator. He traced one of the longer equations idly, not really trying to understand it—just appreciating the rhythm of it.

After a moment, he rolled over again and reached under his bed.

Buried beneath a half-broken Gameboy, an old coloring book, and a hoodie with a suspicious stain was a tiny spiral notebook with glittery stars on the cover. The thing looked like it had been through a war.

Leo opened it to the first page, where a younger, messier version of his handwriting screamed in permanent marker:

“IF I HAVE A SOULMATE, THEY’RE PROBABLY REALLY COOL. I HOPE THEY LIKE SPACE.”

He snorted.

“Past me had great priorities,” he mumbled.

He flipped a few more pages, finding bad doodles, song lyrics he swore were original (but weren’t), and whole conversations with no one in particular. Just things he’d wished he could say to someone. Somewhere.

“I wonder if you ever read any of this,” he said aloud, glancing down at his arm again. Probably not, or else he would've gotten an answer years ago. Maybe there was a time limit to these things? Or like, an age limit? Hell if he knew. 

There was something comforting about it though—like he wasn’t as alone as he thought. But that was just the fairytale part, right?

Still…

Leo picked up a pen from his nightstand, hesitated, then gently wrote just above his knee:

“Do you like space?”

The ink sank into his skin, clean and permanent—at least until he decided to take a shower.

He waited.

Nothing came back.

Leo smiled to himself, set the pen down, and flopped onto his pillow.

“You’re probably asleep,” he murmured. “Guess I’ll wait.”

Chapter Text

The door slid shut with a soft shhhk behind him, and Donnie finally let out the breath he’d been holding.

He paced.

He paced hard.

One hand clutched his tablet against his chest like it might shield him from the reality he was living in. The other ran through his bandana tails and yanked. Hard.

“He doesn’t know. He doesn’t know. He can’t know,” Donnie muttered, circling his room like a glitching Roomba. “He would’ve said something. He would’ve—he would’ve asked.”

He stopped. Turned. Paced the other way.

“This is fine. It’s fine. Just because he never covers his arms doesn’t mean he knows—he could just be lazy. He is lazy. That tracks. That’s normal.”

He threw the tablet onto his workbench like it offended him and started yanking off his goggles.

“Besides, maybe it’s not even me. Maybe he’s got another tech-obsessed freak writing on him somewhere. There are plenty of socially challenged geniuses in the world, right?”

He paused mid-rant, glancing down at his own forearm—still smudged with that familiar shade of ink, still stained with the evidence of his latest mental spiral.

He groaned and slumped into his chair, hands dragging down his face.

“God, I am the socially challenged genius,” he mumbled into his palms.

He let his head thunk back against the metal rest of the chair and stared up at the ceiling, trying to clear his mind.

And then he felt it.

That unmistakable tingle just above his knee.

His breath caught. Slowly—slowly—he raised his oversized leggings to peek at what was written.

“Do you like space?”

It was written in slightly loopy, uneven letters. Too careful to be rushed, too hesitant to be meaningless.

Donnie stared at the words like they were a landmine. His heart thudded against his ribs, his brain short-circuiting in real time.

“Do I like space?” he echoed aloud. “Do I like—what kind of question is that?!”

He shot out of his chair and started pacing again. His legs didn’t know where to take him, so they just took him in a tight circle while he flailed his arms like he was trying to launch into orbit.

“Do I like space?! Leo, I’ve built six telescopes! I have a dedicated NASA livestream open at all times! I made Mikey cry with my Orion Nebula slideshow!”

He froze. Turned to his desk. Slowly, delicately, he picked up a pen.

His hand hovered over his other arm.

But he didn’t write.

Instead, he dropped the pen, shoved both hands into his pockets, and whispered to the empty room:

“…You can’t know it’s me.”

Because if Leo did know?

He might not like the answer.

Chapter Text

It had been exactly forty-three minutes since he wrote the message.

Not that he was keeping track.

Okay, he was absolutely keeping track. Leo had stared at the little line of words above his knee until his vision blurred. Then he stared harder. Just in case his soulmate was waiting for some kind of mental handshake to reply.

But there was nothing. Not even a doodle. Not a dot. Not a smudge.

He exhaled sharply and flopped onto his back again, limbs starfished dramatically across his bed. The notebook lay open beside him like a sidekick in mourning.

“Cool. So maybe they’re just… busy. Or they didn’t see it yet,” he muttered to the ceiling. “Or maybe they hate space. Which is… sad. But valid. Space is a little scary.”

A beat of silence passed.

“…But c’mon, who hates space?”

He sat up, legs dangling off the bed, and stared at his knee again. His fingers brushed the sentence like he could coax an answer out of it. Still nothing. It looked exactly the same as it did nearly an hour ago—pristine, clear, untouched.

Leo frowned.

“Okay, this is fine. I didn’t expect an answer. It’s not like I’ve been waiting for one since I was, like, five years old or anything. I am an adult. I do not need validation from a mysterious arm writer.”

He closed the notebook with a snap and stood up.

Walked over to his dresser.

Paused.

Looked at his arms in the mirror, inked with messy equations, different from his own handwriting.

“…Okay but what if they did see it and decided I was lame?”

He pulled a hoodie over his head—half out of habit, one he rarely did unless he was upset, half to hide the equations and lists like they hadn’t already seared themselves into his brain.

“Whatever,” he said to the empty room. “I’ve got bigger things to deal with than a quiet soulmate.”

The hoodie sagged off one shoulder. The words peeked out anyway.

Mocking him.

Leo groaned, pulled the hood up, and marched toward the kitchen.

“If I’m gonna get ghosted by someone I’ve never met, I’m doing it with cereal.”

-

-

-

The words were still there.

“Do you like space?”

Scrawled on his leg like a cosmic post-it note. Innocent. Friendly. Dumb.

“Wow,” Donnie muttered, slumping further in his chair. “Riveting. Groundbreaking. Pulitzer-worthy journalism.”

He tossed a screwdriver in the air, caught it, and used it to scratch behind his head. Because God forbid he do anything productive while the most annoying sentence in the universe mocked him from his thigh.

“Do you like space?”

He read it again, voice dripping with sarcasm.

“No, I hate physics and the fundamental mysteries of the galaxy. I loathe black holes. The vacuum of space? Ew. Absolutely not.”

He threw the screwdriver across the room. It clattered harmlessly against a toolbox and startled a stack of notes off the edge of the table.

“I mean—what kind of question is that?” he asked the ceiling. “You finally build up the nerve to contact your literal destined soulmate and that’s the opener? Not a ‘Hi,’ or a ‘What’s your name,’ or even a ‘Do you believe in fate,’ just—‘Do you like space?’”

Donnie leaned forward and grabbed a tablet off the desk, idly scrolling while his other hand traced over the older notes inked into his arms.

“Redesign the servos on the crawler legs.”

“Need more hex screws. Check Michael's weird stash.”

“Don’t forget to recalibrate the gyros before Nardo breaks something.”

They were faded but present—little records of a brain that couldn’t shut up even when his mouth did. It was sort of surprising that Leo never asked about anything he wrote down, especially when their names were involved, but maybe he chalked it up to coincidence. Or maybe he really was just that dumb.

The marker hovered in his hand. He stared at the message. Again.

He could respond. He should respond. It would be the polite thing to do. But it would also be the Donatello thing to do, and that guy? He overthought everything.

He squinted at the sentence like it personally offended him. “What if I say yes and they follow up with a question about astrology? Am I supposed to pretend Mercury being in retrograde affects my lab work?”

Donnie exhaled and shoved his goggles up onto his forehead. “Okay. New plan. I ignore it. I let the question live on my skin forever like a tattoo from a bad first date. Soulmate roulette continues. No big deal.”

He stood up dramatically, hands in the air like a game show host. “And for my next trick, I’ll pretend this is totally fine and I’m not spiraling internally at all.”

He turned to go grab a soldering iron—and promptly tripped over the hoodie Leo left on the lab stool.

Donnie stared down at it. Blinked.

“…Hoodies are betrayal,” he muttered, stepping over it. “You were cool once.”

But the words still burned on his leg.

And the marker? Still in his hand.

Before Donnie can make a move, the lab door slams open with a thud and Mikey bursts in, looking wildly around.

“Donnie! Dude! Have you seen my art markers anywhere? I swear I left them in my room, but now—poof—gone!”

Donnie freezes mid-step, marker still clutched between his fingers.

Mikey grabs a nearby drawer and yanks it open, sending a small avalanche of colored pencils onto the floor.

Donnie smirks, shaking his head. “You know, if you spent half as much time organizing as you do losing things, you might actually find what you’re looking for.”

Mikey shrugs. “But then where’s the fun in that?”

Donnie glances down at the stubborn question still inked on his leg and mutters, “Meanwhile, my soulmate is probably wondering if I’m weird for talking to my own skin.”

“Maybe they think that, or maybe they think your equations are cool or something.” Donnie watched Mikey rummage through the drawer like a whirlwind, scattering art supplies everywhere. The kid really was relentless when it came to his markers.

Then, out of the corner of his eye, something caught Donnie’s attention.

A few faint words appeared on Mikey’s forearm, curling like a living script. Donnie’s brows furrowed as he leaned closer, heart doing a subtle flip.

The handwriting was unmistakable—rough, bold, and definitely Raph’s.

“Any plans for dinner?.”

Donnie blinked, then looked at Mikey, who was busy muttering, “It’s barely even past lunch..”

A slow grin spread across Donnie’s face. “Wait a minute. You two are soulmates?”

Mikey froze mid-search, then grinned sheepishly. “Yeah, kinda! I like to draw on myself, and Raph scribbles stuff back when he can. Mostly questions or praises to my art.”

Donnie shook his head in amused disbelief. “How did you even find that out?”

Mikey paused his search for his art markers, leaning against the nearest table. “Well, I think I was painting something when I accidentally flung my paintbrush and got paint all over me, and when I went to go wash it off, I saw Raph desperately trying to scrub off the same paint but it wasn't getting off of him. It was sort of funny to see him like that.” 

Donnie gave a soft laugh, imagining the whole scene. “Well, at least your soulmate isn't dumb as a rock.” 

Mikey snorted, shaking his head before giggling as he found his markers in a small cardboard box by the table he was leaning on.

“Leo isn't dumb, he's just oblivious. Anyways, I found my art markers! I'll talk to you later Dee. Have fun answering that stellar question.” 

Donnie rolled his eyes as Mikey shut the door behind him, leaving him to the thin black lines on his thigh, just above his knee. 

“Do I like space?” Donnie tapped his fingers along his skin before grabbing a fine tipped marker and answering below.

“Did Galileo like astronomy?"