Chapter Text
If Donnie had to measure noise pollution in decibels, Casey Jones would break the scale.
The boy was a walking siren—laughing too loud, talking too loud, existing too loud. Especially when April was around.
April. Donnie’s eyes trailed over to her, where she was giggling at something Casey had said, her hand over her mouth with an amused look. Donnie had seen an uptick in that look directed at Casey recently, it made a spike of both insecurity and jealousy flare up in his chest.
Maybe when he was a teenager, he would’ve gone over and separated them. Not caring about the annoyed and frankly unsettled look that would cross April’s face when he violently pulled them apart, but Donnie was an adult. He no longer had the benefit of being a teenager, making stupid decisions.
So he did the next best thing, longed from afar.
“C’mon, Red! Casey Jones isn’t going to let any Purple Dragons get us tonight. You can hold onto me if you’re scared.” Casey batted his eyes at her teasingly, his voice was stuck in that flirty drawl he almost always spoke to April in. He had that Casey-Jones brand of charming on his face. A smile that was all missing teeth and immaturity. Casey was balancing his hockey stick on his shoulder like it was part of his spine. That grin could probably be seen from orbit.
“Oh yeah, I’ll totally be holding onto the guy who got his butt whipped by them on multiple occasions while swinging a hockey stick around instead of a normal weapon..” April replied dryly, playfully punching Casey in the arm and giggling as he winced.
“Red, normal weapons are cliché, and I don’t do cliché. Plus, it’s got style! You ever try a slapshot to a Kraang bot? Satisfying, man.” Casey quipped with a grin.
Donnie looked away, the camaraderie between the two of them twisting the knife that had been permanently lodged in his heart since Casey had come into the picture when they were teens. He stared out at the city below, distracting himself by doing what they were supposed to be doing, patrolling.
Leo, Mikey, and Raph had all taken the East side of the city. Donnie knew why Leo paired the three of them together; for all the weird drama simmering under the surface, they were almost perfectly synchronized in battle. Donnie sort of wished he could’ve stayed with his brothers, though, and not here watching the girl of his dreams since he was a teen, and none other than Casey Jones banter like they just clicked. Clicked together in a way Donnie never did with her.
He was so lost in his spiraling thoughts that he hadn’t even realized Casey was now next to him until the human clapped him on the shoulder with a big grin. “I’m sure Donnie could use some protection. Remember when he got beaten up by a monkey?” Casey mocked, talking about the turtle like he wasn’t there. Donnie scowled, already hating the way Casey’s grin widened at his reaction. Donnie aggressively shoved Casey’s hand off him, pointedly staring down at the ground again for any activity. He knew he shouldn’t indulge Casey like this, but the human seemed to always know just the way to get under his green scaly skin.
Donnie tightened his grip on the ledge. “For the record, I could design a device that measures human obnoxiousness,” he said dryly, a forcibly bored expression on his face. “You would break it. Your levels of arrogance are simply a scientific marvel.” He hissed that last part, giving the human a lethal glare before returning to the bored one, decidedly not feeding any more into it. Casey opened his mouth to say something when he was (Thankfully) cut off by April.
April rolled her eyes. “Guys, can we please focus? The purple dragons have been spotted near the docks again.” She sighed, sending Donnie a small smile that made his heart do a somersault as he took her usual surveillance space right next to him. In the past, Donnie would’ve gloated, sent Casey a smug look at the attention from April, but not anymore.
He was a mature adult. So he just gloated in his head.
That quieted Casey—somewhat. The night smelled like damp metal, cigarettes, and trouble, and the three of them were the current protectors of the East side of the city.
Donnie felt eyes on him, scales prickling from the intense feeling of being watched.
Alarm bells rang in his head, his eyes scanning the area with mechanical precision usually only applied to his inventions.
Then—he found the perpetrator, and it wasn’t some purple dragon planning to attack them; it was Casey.
Donnie stared back at the human in confusion. Casey looked deep in thought, honestly a little upset. It wasn’t that upset reaction he usually saw from Casey when the human would see him and April together, it was almost hurt. Donnie weirdly felt a pang of guilt, even if he was completely oblivious to what he could’ve done to make Casey have that…look on his face.
“Uh…guys? What are you doing?” April asked in confusion as she stared at the two of them. Casey broke out of it immediately, averting his eyes and clearing his throat awkwardly with a forced-smug smile. “Just a staring contest, you know how it is.” Casey shrugged as if there was any world where Donnie would be willing to participate in a staring contest with him.
Donnie rolled his eyes. “Jones has a staring problem. That’s what we were doing.” Donnie corrected dryly, crossing his arms and pointedly avoiding Casey’s gaze. He could see Casey fidget slightly out of the corner of his eye, but paid no mind to it as his attention was grabbed by a bulky man, dressed way too nice to be wandering around this late at night.
Ridiculous sunglasses? Check. Tattoos? Check. An ungodly amount of body spray that Donnie’s nose could pick up even from the rooftop? Check.
“Hun’s here. I’ll send an alert to the others.” Donnie whispered, already sending out the silent alert he had designed on their T-Phones for stealth missions.
“We should wait for them to come before we move in—” Donnie started explaining before he was promptly cut off by—
“GOONGALA!” Casey practically battle cried as he slid down the fire escape, immediately in pursuit of a now retreating Hun as both Donnie and April stared after him slack jawed.
This was it. Casey Jones was going to be the reason he committed murder tonight.
“That…” Donnie’s voice started almost breathlessly in disbelief. “IDIOT!” Donnie hissed, hand squeezing like he wanted to shake some sense into the vigilante currently in pursuit.
“Wait here, April!” Donnie seethed over his back as he stood from the roof, sliding down the fire escape with much more grace and a lot more stealth.
He could hear Casey yelling corny quips as he stupidly put himself in danger, “Class is pain 101, instructors Casey Jones!” He heard the human yell from ten feet away. Donnie was rapidly catching up, twenty years of ninja training making your legs stronger, will do that to you.
Then came the noise. A sudden whirring behind the shipping containers—that Hun had led the both of them to, metal claws glinted in the dark, the faint magenta glow of Kraang tech through the darkness. Donnie reached out to snag back Casey, but before Donnie could even have a second to warn him, Casey was already charging forward.
“Nowhere to run, now!—” Casey yelled, hockey stick raised to hit, but the impact never came. A clawed Kraang tech arm had clamped around Casey, throwing the human with an almost lethal force into a shipping container.
“CASEY!” Donnie screamed, running over to the vigilante with his heart beating out of his chest.
When Donnie got there, Casey was sprawled across the concrete, mask cracked, and blood trickling down his temple.
And that’s when Casey went silent for once.
He had carefully picked Casey off the concrete, seeing the flash of red, blue, and orange masks from the corner of his eye and the aggressive metal clink of weapons hitting together.
But Donnie wasn’t paying attention to any of that.
Casey’s heart was still beating; that was all that mattered. He held Casey in his arms, grimacing slightly at the blood that hit his scales.
“Dude…is Casey?” Mikey asked from behind him, the next words on his lips clearly being ‘dead’. Donnie whipped around, watching as Raph locked eyes with a bloodied and unconscious Casey before turning around to angrily beat the ever-loving shit out of now tied up and defeated Hun while Leo desperately tried to pull his brother off the purple dragon leader.
“Casey is alive. That’s all that matters. We need to get back to my lab…now.” Donnie said with a calm firmness. Betraying the panic currently welling up in his gut.
Donnie laid Casey on the makeshift med bay he’d made in his lab. He and his brothers couldn’t exactly go to a normal human doctor, due to both the screaming humans that would run away in fear, and also the fact that they didn’t exactly have the anatomy that doctors studied. So Donnie had appointed himself as the ‘family’ doctor. A role he’d taken even more to after Master Splinter had passed.
The team worriedly loomed over Casey. Leo and Mikey on either side of the bed while April watched worriedly at his feet. Raph was in the doorway, trying to seem calm even with the situation, but the way his teeth grinded and he tapped his foot on the ground impatiently said otherwise.
“Donnie, will he be okay?” Leo asked, his voice stuck in that ‘leader-Leo’ tone. Donnie knew that look in his brother’s eyes, it was the one he got when he was hiding his panic under a veil of leader-like calmness.
“I don’t know yet, Leo.” Donnie sighed as he set up the medical monitor, clamping a pulse oximeter to Casey’s finger to track his blood oxygen levels. They always thought he knew everything, especially in times like this. He understood this worry, but he wouldn’t be able to answer if Casey would be okay until he was able to run a full scan of the human.
“From the looks of things, he sustained a major head injury…but other than that I’ll need some time to scan him for injuries,” Donnie explained, tapping the keys on his monitor to start the diagnostic process.
“How much time?” Raph growled worriedly from the doorway. The room fell silent as all eyes locked on Donnie.
“I just need time, Raph. An hour or two at most…just wait outside of the lab.” Donnie explained, clearly exasperated but trying to keep his temper in check for the sake of his worried family.
Each one of them trailed out, one by one.
It was the quietest Casey had ever been…but Donnie found he didn’t enjoy the silence as much as the thought he would.
He kept looking over at Casey, almost expecting the vigilante would wake up with a cave-mouthed smirk, quipping—“You worried about me, Don?” In a taunting voice, but it never came.
The scan had told him some of what he already knew, and some of what he didn’t. Casey had suffered a traumatic brain injury, that much he could tell from the gauze he had to carefully wrap around the human's head, but the damage looked worse than Donnie had originally thought.
His brain waves were all over the place, most of them barely reacting. Donnie suddenly wished he had an MRI in the lair to be able to see more thoroughly. Just another thing to build added to the list.
Donnie let out a long sigh, cracking his neck and stretching. He had been at this for an hour now, and the best news he had for the team was that Casey wasn’t brain-dead.
He saw a sudden change in brainwaves, blinking at the readings and suddenly leaning forward with interest, typing wildly as he logged the changes.
Then—
he felt the prickling sensation of eyes on him again.
He moved his head, now locking eyes with Casey, who was staring at him with a blank expression.
Donnie stared back silently, waiting for any Casey-isms to come out of the vigilante's mouth but none did.
“Hey…Jones. How do you feel?” Donnie asked calmly, a hint of nerves he couldn’t quite shake lodged in the back of his throat. He was approaching slowly, like he was worried he was about to be attacked by a wounded animal. That expression wasn’t Casey; that human was always brimming with life, not this…hollow shell with Casey’s face that had his chocolate eyes locked onto Donnie like a homing missile.
“Casey…? Earth to Casey…?” Donnie asked, waving a hand over the human's face as the spark of hope drained from his heart as Casey still wouldn’t talk.
‘Oh, this is so bad.’ Donnie’s brain screamed, already computing fifty different ways that breaking the news of Casey being awake but practically an unresponsive shell would drag the lair into worry-ridden chaos.
Then—
Casey blinked, his eyes filling with a spark of something besides emptiness and before Donnie could process the shift, Casey spoke.
“Whoa! Who’s that fine babe?” Casey yelped, putting his hands on his face in shock.
Donnie blinked, utterly dumbfounded by the idiocy that just left the hockey player's mouth. Donnie looked to the lab doors, expecting to see April, but found nobody there.
There was nobody in the lab besides the two of them.
And Casey’s eyes were trained on him.
“F—Fine babe?!” Donnie squeaked incredulously, almost falling back into the monitor in shock, before shaking his head with a completely befuddled expression. “Patient is most likely hallucinating,” Donnie grumbled to himself as he cleared his throat awkwardly and walked over to Casey’s side.
He grimaced; if Casey was talking about him (an unlikely hypothesis), that meant that he didn’t remember who Donnie was. Which was already somehow almost less concerning than the fact that Casey had possibly called him “Fine babe” In the first place. He must’ve hit his head really hard if he was hallucinating some beautiful woman in Donnie’s place.
Casey glared after a moment, pointing at Donnie accusingly right in his plastron as Donnie blinked in confusion. What was Casey doing?—
“Who are you? I don’t think I ordered any sexy turtle people to visit me!” Casey said accusingly, like Donnie was somehow some rando who broke in, and Casey’s now clearly amnesia-ridden-brain has decided the best course of action is to call the intruder sexy.
Wait…sexy?
S—SEXY?!
Donnie makes a sound like a dial-up modem glitching out, his entire face flushing bright red.
“SEXY—?!” Donnie sqawks, voice cracking spectacularly. “I—you—excuse me, I am conducting vital scientific protocols, Jones! Not some…some rom-com montage!”
His hands fly up to pull on his mask tails—an old nervous habit—before he remembers he’s supposed to be helping Casey, not scandalized by whatever nonsense is coming out if his confused injured brain.
“Tch, you wouldn’t recognize ‘sexy’ if it hit you in the head with a hockey stick.” Donnie muttered, more to himself than to Casey. Needing to at least get a little jab out of his system. The fact that Casey had called him a ‘sexy turtle person’ meant one of two things—
Either A. Casey was hallucinating a pretty turtle girl in Donnie’s place,
Or B. Brain damage had made Casey attracted to him. (The more terrifying option)
“Stop spewing absurdities while I slave away trying to fix your scrambled brain-meat.” Donnie scolded, adjusting the pillows and the blankets for Casey, who had his eyes fixed on Donnie with a quizzical glare.
Casey huffed, shaking his head slightly before Donnie reached down with a dry look and held his head still to make sure the gauze stayed in place.
“Yeah sure, you’re bein’ scientific,” Casey said in air quotes. “I know what you’re trying to do! You’re trying to seduce me! I see those long legs, you’re literally not wearing any clothes!” Casey pointed at him accusingly again.
Donnie had no idea what to say at this point. He’d never been talked to in this way, called these things, or blatantly accused of seduction like he was even capable of such a thing.
Donnie makes a high-pitched wheezing noise, like a robot short-circuiting under the weight of sheer absurdity. His hands fly to cover himself, completely scandalized, as he glares at Casey with indignation.
“NOT WEARING ANY—?! I AM LITERALLY A TURTLE! THIS IS MY BODY! THESE ARE SCUTES, YOU HEATHEN!” He gestured to himself while he squawked in offense.
(He absolutely does NOT glance down at his 'long legs’ which are currently doing nothing but existing awkwardly. Nope. No way.)
There's a beat of stunned silence, Donnie contemplating the idea that he might be the one with the brain-damage and all of this is an elaborate hallucination.
“You think I, Donatello Hamato—genius, ninja scientist, and clearly the most suffering turtle alive right now—would stoop to...seductive subterfuge?!” He hissed, and his voice definitely didn’t crack on the word ‘seductive’.
Donnie clutched his head like the weight of this ridiculousness was about to make his brain explode. “Of all possible memory malfunctions—why is this the one your brain lands on?” Donnie lamented to himself, already sensing that this was about to be a test of Donnie’s ability to deal with Casey.
Donnie peered down at his legs, confused by what Casey was currently seeing when all Donnie saw were green, freakish legs, ‘Are my legs actually...?…nope. He’s brain damaged. Don’t read into what he says.’ Donnie reminded himself.
Casey sighed. “Come on, man! You’re trying to do something! You show up to…” Casey paused his rant, his eyes scanning the lab with not a hint of recognition.
“Wait—where am I?” Casey asked cluelessly, Donnie’s worst fears being confirmed with every word that left the human's mouth.
Casey’s eyes trailed back to him, an almost scared look etched on his features.
“Who am I?” Casey asked in a whisper.
Donnie’s anger evaporates instantly, replaced by something much heavier coiling in his gut. His shoulders slump as he exhales sharply through his beak—part frustration, part mental and physical exhaustion.
He reached to gently push Casey back on the bed as the vigilante tried to sit up. “Don’t move, you’ll make it worse.” Donnie whispers, an uncharacteristic softness in his voice.
“Okay. Okay, okay, okay—” His voice was softer now, strained with a forced calmness. He didn’t want to scare Casey, especially not after the memory loss the idiot had gone through.
“You are Casey Jones. Vigilante. Pain in my shell 87% of the time. You—you fight crime with a hockey stick because…” Donnie stopped before recalling what Casey had said before all of this went down. “Because you think normal weapons are cliché, and you don’t do cliché…and it apparently has style,” Donnie whispered, that heavy feeling coiling around his heart like a vice before he pulled it off and cleared his throat. “And you once ate an entire pizza while hanging upside down from my lab railing just to prove you could.” Donnie huffed.
A pause. He rubbed his temples before his eyes locked on Casey's stupid vigilante mask that Donnie had put on his lab table next to Casey’s bandana. Casey had used the same skull painted one since they were teenagers. Something clicks in Donnie’s brain—a desperate idea forming behind his eyes. With sudden purpose, he marches over to the blood-stained mask, picks it up, and shoves it into Casey’s hands like a lifeline.
“Here. Maybe…maybe if you hold this stupid skull mask long enough, it’ll reboot whatever nonsense code got corrupted in that thick hockey skull of yours.” It wasn’t a real theory, but desperation breeds terrible science.
He watched as Casey blinked at the skull-painted mask in his hands, Donnie hoping against everything he knew about amnesia that maybe, just maybe, Casey might have a flicker of recognition in his eyes.
Donnie almost thought he might’ve done it for a moment—as Casey looked up at him, a flicker of something in his eyes.
Instead of “Hey, gaptooth.” Or whatever Casey-Jones brand of insult Casey would refer to him as in this moment—
“Are you not my boyfriend?” Casey asked bluntly, a completely serious look on his face.
Why did he think that in the first place?!
Donnie chokes on his own spit, nearly tripping over his bō staff that was propped up against the lab door as he backpedals so hard his shell thunks against the wall.
“BOYFR—?!” He swore his voice reached a frequency of sound only dogs could hear. “NO! No…we are—NOT! We hate each other's guts 70% of the time, and the other 30% is just begrudging co-existence.” Donnie flailed his hands around to make his point, but instead, it made him look like the most flustered turtle on earth.
A beat of silence. Then, with a forcibly dry look (and zero eye contact), he adds:
“…Also, you’re literally incapable of being quiet. And I…have standards.” (liar. He fell for the first girl he ever saw.)
Casey blinked at him. “Really? That blows, I figured I would’ve bagged a hottie like you as fast as possible.” Casey didn’t even sound flirty, just honest and if Donnie was hearing right—disappointed.
Donnie can’t seem to keep control of his voice anymore. It just keeps jumping octaves against his will. Maybe he’s actually dying? He can actually feel the heat emanating from his face at this point—but no. He can’t panic. Not when Casey is in front of him, confused and injured.
Even if being called a ‘hottie’ made his brain feel like it was about to explode.
(Deep breath, Donatello. Remain rational.)
“You—you can see me, correct? Is your vision impaired? I am a turtle. I have no attractive human features. I mean, I don’t even have lips or hair!” Donnie was desperately trying to make Casey change his mind about the sudden, apparent attraction to him.
Donnie gestures wildly at his own face, like that’ll somehow prove his point, gap-toothed grimace fully on display. “And yet somehow—somehow—your brain has decided now, of all times, to develop atrocious taste in men?” He immediately regrets phrasing it like that. His hands fly up nervously before he even has a beat after his sentence.
“Wait. No. That sounded wrong—I mean, objectively wrong! Like, scientifically speaking!” (Smooth recovery. 10/10) Going into scientific rants, the perfect way to stop anxiety. “Not that I’m technically classified as a man! Or—wait, no, I am, but not human, so the term is debatable and—OH SHELL, CAN WE PLEASE FOCUS ON YOUR BRAIN DAMAGE?!” Donnie held his head in his hands, utterly distraught by the word vomit that just left his mouth.
Casey blinked cluelessly.
“I have brain damage?” He said innocently as Donnie stared dumbfounded.
This was about to be a long recovery process.