Chapter Text
System: loading…
There's a buzzing in his ears.
Bodily functions. Cardiovascular system. Cranial pressure. Proprioceptive hypersensitivity. Emotions. Tears.
Reboot. Reboot!
Breathe.
He gasps quietly in response to his urgent demand for oxygen, his diaphragm quavering like the steady rattle of a metro car over ancient rails. He tries to find some sort of solace in the thought of familiarity, but there is none. The subway is home, but there is no home without Leo.
Leo…is gone. That much is plainly certain. There’s no surviving what his brother must have just gone through on the other side of that explosion. Sacrifice, then. Pure and simple, and yet Donatello, for all of his illustrious self satisfaction and prodigious youth, cannot pin together the pieces of this puzzle with any of his customary flagrant triumph. They’ve suffered near defeats by the hundreds, but never something like this. He's never experienced unmitigated, categorical failure. A complete loss. A massacre.
Death. Life's most absolute absolute. He swallows. He breathes. He cannot handle much else.
Donnie’s thoughts, usually so organized, swim in his mind like the shreds of a thousand pages, weighed down with wetness and soot. Nothing makes sense and yet everything does. Leo is gone. Leo is dead. His lungs feel leaden and his shoulders ache with the hitch of sobs he’s subconsciously trying to dampen.
System: overload.
And then Mikey is doing the impossible.
His chest aches with feelings he's entirely unwilling to acknowledge, but it happens nonetheless. Remorse. Despair. Fear and desperation. He resorts to impulse and mirrors his eldest brother, clasping onto Mikey’s shoulder like a vice to carry the load of whatever the hell he’s doing with his hands. It stings like shards of ice, overwhelming his senses to the point where he can no longer see, only feel. It’s a heavy energy, spiked with the sobering notion that this could be it for all of them, and Donnie gnashes his teeth against the shockwave he has no idea how to ride.
“...took you guys long enough.”
Battered and bruised and still running his stupid mouth, Leo appears in sharp relief to the contrast of the night behind him. Framed against the corroding bodies of ancient gods scattered across a dimensional universe he’s only ever theorized about, Donnie watches the creation of a bifurcated timeline, a variegated multiverse, a chain of events that supersedes all space and time. It’s simultaneously fascinating and horrifying, and a thought to ponder another time because the creature responsible is still after his brother and Raph is reaching—
Fury.
His heartbeat pounds in his ears, all static and madness and pain. He’s never felt this much pure vehemence singing through his blood and he acts on it, drawing everything he has left into an attack that he doesn’t even consciously think about. It just happens, mystic energy and violence spurring from the end of his bō, and there’s nothing he’d rather see than that creature’s — that deplorable, reprehensible creature's — guts on the business end of his drill.
Vengeance.
He wants it, fiercely. Revenge, rabid and feral, thuds through his system like amphetamines. Never one to fall on pure instinct, Donnie naturally does exactly that. There’s no room for rationality as he drives his weapon straight into the alien’s eyeball in the same animalistic way the Kraang’s tentacles had driven into his older brother’s skull. There’s no room for logic when all he wants to do is crush and rip the Kraang apart for forcing his twin brother to sacrifice himself while beating the snot out of him in the process.
The Kraang escapes his attack, but by then, Donnie has drawn up all of the variables for distance and force in his head. He bellows, letting his mystic bō disintegrate into the ether for a better, more pertinent focus, and grasps his brother and yanks.
“Leo!”
He’s on his knees in an instant, already searching the blue banded brother’s expression for signs of consciousness, anything. For the love of whatever deity he can think of, for the science he so desperately clutches to his chest like a crutch to stave off the inevitably that it might fail him one day — and that day could be this day — he needs, he desperately needs his brother to be okay or Einstein help him, he will tear another interdimensional portal open with his bare hands and strangle the Kraang himself.
Leo’s eyelids flutter, then open slowly. It feels like a decade, but he’s making noise and garbling some nonsense about Staten Island and Donnie just wants to shake him or something because he’s overwhelmed and overstimulated and overwrought and over just about everything that has happened on this day and—
Emotions.
They’re not his thing, but right now, he can’t help but acknowledge that they’re very much his thing right now. Years of repressing them, categorizing them, and carefully filing them in mental folders for future consideration has forced the carefully safeguarded vault in his mind to burst. The veil of control he wears is torn and he’s barely holding it together as it is, adrenaline and testosterone flooding his usually carefully controlled demeanor, affecting him in all sorts of ways. He’s elated and relieved as Raph wraps the three of them in his arms, shaking and sobbing beyond reason. He’s panicked and anxious as Leo gasps for air, fresh blood pooling at the corners of his lips and the swell of his brow. He’s sweating and distracted as he tries to find a way across the narrows to Manhattan using what little energy he has left to construct a mystic motor with the tip of his bō. He’s cursing under his breath and holding back a snarl as he crashes the side of the water taxi against the quai, knowing any movement might make his brother’s condition that much worse. He’s all cortisol and stress and terror under the shroud of a barely strung together composition of what he thinks calmness might look like.
A glance at his reflection in a shard of glass tells him that he’s achieving none of these things.
Leo’s mostly awake, which is better than Donnie could have hoped for as Raph gently sets him over his shoulder for the walk home. The largest of his brothers needs his arms free for clambering through the debris and Donnie follows in their wake, alternating between scanning Leo’s various bodily systems and keeping an eye on Mikey as he stumbles through the rubble. The youngest of them winces, unable to keep his burnt fingers away from his mouth in an attempt to soothe the sting of ripping a hole in spacetime. It’s horrifying, honestly, and Donnie holds his breath.
System: diagnostic testing.
Multiple contusions. Hypertension. Acute cephalgia. Tachycardia. Panic. Anxiety.
Reboot. Reboot!
Breathe.
“Hey, Big Guy.” Leo groans, tapping the largest of their brothers on the shoulder for attention. Donnie snaps back into focus and stops, arms already outstretched as though Leo will start crumbling at any moment. “Can you let me down for a minute? I need a sec.”
Raph murmurs his concern and sets him down on the closest steel beam, his gaze never wavering from taking stock of Leo's injuries. Donnie’s on him in a moment, goggles down to run a subroutine to compare Leo’s ongoing condition against his baseline data from the top down. The results that trickle in are worrying, but not life threatening; a significant concussion, multiple hairline shell fractures, facial swelling…
“What, did I grow a third eye or something?”
“Leeeettttt’s not talk about eyes, shall we?” Donnie flips his goggles back over the crown of his head and glances at Raph’s reaction, hoping the poor excuse for a joke flies over his head. It doesn’t, of course; Raph is far too susceptible at the moment, no doubt because he was taken and brainwashed and turned into a soulless servant for a hoard of evil aliens hellbent on world domination and—
Breathe.
Donnie inhales, grappling to get a hold of himself, and promptly draws the unwanted attention his way instead. “You alright?”
“I’ve been better,” Leo's lips pull into a shaky grin, which only serves to accentuate the coagulated blood on his chin. “Although I can’t imagine I look any worse than you.”
“And the barbs never cease,” Donnie replies, thoroughly unable to go tit for tat at the moment. He’d make up for it later, when Leo was safely in their lair receiving the medical help that he so desperately needed; that they all needed. He needs to look at Raph’s watering, bloodshot eye and the laceration on his shoulder. He needs to bandage Mikey’s scalded skin before the bacteria in his youngest brother’s mouth gets his burns infected.
Scowling, Donnie leans over and presses himself up beside his twin, wrapping his arm around his shoulder so as to support his weight. Leo’s surprisingly heavy for someone who’s a whole inch smaller than him, and the burden makes Donnie’s limbs shake slightly with effort. They stumble as Leo responds, slapping his lips together wetly in his ear in an attempt to be his usual obnoxious self. Donnie has enough perspective to know when Leo’s projecting and doesn’t snark back, which is unusual, but there’s been nothing usual about this particular adventure.
Around them, New York City burns.
~
“There’s something seriously wrong here…” Donnie, now safely within the confines of their lair, shakes his head in disbelief. “We have to wake him.”
“It’s about time anyway,” April says, checking the time on her mobile. “He’s been out for over an hour.”
Donnie gestures for Raph to step back and keep applying salve to Mikey’s forearms. “Just in case. We don’t know how he’ll react.”
Raph nods and Donnie pointedly ignores the pained expression on Mikey’s face as he turns his attention back to Leo. In the time since they’d returned, Donnie had tended to the worst of his injuries. With the cracks in his shell sealed with resin, Donnie focused on the second most concerning issue at hand, which was the plethora of cracked ribs in his abdomen just waiting to make mincemeat out of his internal organs. Leo’s plastron did its job, more or less, but the damage he must have taken was beyond comprehension, which brings him to his current problem at hand.
Donnie chews on his lower lip for a moment before carefully prying one of Leo’s eyes open. “I know you’re in there. Earth to Nardo, come in.”
“Nerd,” Leo grumbles. It’s a terrible comeback but, by Galileo, it’s the sweetest sound he’s heard in a while.
“Your scans are coming up…weird.” Donnie glances back at the computer screen behind him, a weight building at the base of his shell. His entire body shows evidence of multiple injuries, healed and new, that didn’t correlate with data previously recorded just a month earlier; there’s no way he could have accumulated all of these fractures and sprains and contusions and organ damage in the ten minutes he was locked away. “You heal fast — we all do — but not that fast…”
Donnie swallows, his mouth suddenly dry. “Leo, how long were you…”
“...a week?”
Around him, his family reacts accordingly. Splinter inhales sharply. Raph cringes. April slaps her hands over her lips. And Donnie, whose eyes quickly confirm Leo's rough approximation, feels nauseous. It's a good estimate, but not entirely accurate; based on his own carefully curated extrapolation of their physical anatomy and regenerative processes, Leo's earliest injuries were sustained two weeks ago at the least.
Glancing around, Donnie knows that it's a sobering fact he'll keep to himself for the rest of his life.
“Time passes differently in the prison dimension…” Donnie murmurs, his thoughts already churning in a desperate plea to stop thinking about the what and more about the how. “Improbable, maybe. But there's next to no meaningful research currently being done on the transdimensional spacetime continuum."
"A week?" Splinter stares, his expression wide with anguish. "How…"
"Doesn't matter," Donnie responds quickly, already reaching for the medical tape. "We need to stabilize his ribs. Can you hand me the scissors? This is going to take a minute. Or twelve."
~
“Lidocaine…where would I be hiding if I were—got it!”
Donnie spins around, holding the vial up to his eyes before crossing the distance towards the complaining patient lying on the table. Leo is their usual go-to for medical care, but only because his bedside manner is far more tolerable than Donnie’s sometimes questionable fascination with how things work on the inside. People, especially mutated turtle-shaped ones, are not like machines that can be taken apart and put back together, which means that Donnie is often relegated to observations and note taking only.
But with Leo half conscious and groaning on the table before him, Donnie suddenly feels sick to his stomach with responsibility.
“You’re going to have to reset my ankle,” Leo murmurs, already grimacing. “So dope me up, bro. Put three milligrams in that syringe and hand it over.”
“I’m perfectly capable of finding the injection site myself,” Donnie responds indignantly, swallowing uncomfortably as he jabs the needle into the vial of anesthetic. He taps the syringe before dragging his goggles back down over his eyes, quickly finding the midway point between the two bones that have all but shattered and fused back together beneath the swelling. He swabs the site, heedless to Leo’s arguments about injecting it himself, and depresses the plunger into Leo’s ankle.
“Shhhhhiiii—fuck, that hurt.” Leo swears, and Donnie can’t help but cringe a little at his colourful language. There was no doubt that it hurt and, between the royally misshapen ankle and the rest of his ailments, Donnie can’t blame him for using such blasé vocabulary.
“It won’t hurt for long,” Donnie assures him, tossing the used needle into the appropriate bin. He disinfects his hands for the forty fifth time and glances towards their carefully curated anatomical database for all things mutant and turtley. A snap, a break, and several crunchy twists in the opposite direction should do the trick, but it's going to require him to feel Leo's bones grinding beneath his fingers and if Donatello wasn't convinced he was going to throw up earlier, he's certain he will now.
"It's numb," Leo hisses from his bed, massaging his temple with his uninjured fingers. "Go for it."
Breathe.
~
Space. Time. He’s thought about the words so frequently in the last forty eight hours that he wants to slap himself for not figuring it out sooner. It would have been an obvious connection to make if his head was screwed on straight right now, but he’s turtle enough to admit that he’s too exhausted and achy to walk, let alone think.
Leo makes portals through space. He can’t leave this continuum for another, his powers constrained to popping up from place to place simultaneously. But Mikey?
His portals, as confirmed by Casey himself, delve through the depths of time.
Donnie gulps the latter half of his lukewarm coffee and stares blankly at a pile of debris in the corner of their kitchen. The implications…the consequences of this particular discovery are not lost on the teenage prodigy. The fourth dimension of reality in the prison dimension was never the catalyst to Leo’s all-inclusive vacation in the Kraang Riviera. The critical component in this chaotic mess of monsters and magic was Mikey all along.
He was the one who tunneled through time with his mystic hands. He was the one who timed the portal a week later.
Mikey could never have known it, of course; his youngest brother had no idea what he was doing when he ripped a hole between dimensions. He was relying on pure dumb luck and stubborness when he did it, which is what bothers Donnie the most. What if Mikey had tunneled through time too late? What if he had jumped three weeks forward instead? Or a month? Or…
He doesn’t want to think of the possibility, to be honest, but the ramifications continue to rattle around in his brain and he just can’t shut them off. It’s a problem he’s had for years, the unyielding inundation of facts and ideas swarming his consciousness like an incessant mob of wasps. He wishes he could turn it off sometimes like a switch, but they’re still a long way off from the bionic synergy of man and machine…homicidal aliens aside, of course.
And here comes another wonderful memory that he’d love to banish from his temporal lobe for all of eternity. He’d seen just enough of the ship’s internal memory to catch a glimpse of the hundreds of worlds they’d devoured, including their very own, over the past millennia. The blatant waste of life disgusts him, driving a wave of fury from within that Donnie’s simply not used to swallowing.
Fury. Vengeance. Emotions.
Breathe.
Except breathing, no matter how essential to the continued function of his body, is no longer cutting it.