Chapter Text
If life as a teenage mutant ninja turtle in a mystic world wasn't already unhinged enough, it somehow got worse when Donnie and his brothers were yanked into another dimension by a man calling himself Mister Ogg, just to be forced into a fight.
Not against monsters.
Against another version of themselves.
The other turtles were wrong in a way that set Donnie's nerves on edge the moment he saw them, stark black and white, sharp lines, no color at all. Like living ink sketches.
Smoke swallowed the arena.
The fight was rigged.
They should have won. They had the tech, the training, the mystics. But then Leo slipped just for half a second, and that was all it took.
When it cleared, Ogg's voice rang out, smug and echoing.
"The Mirage turtles are victorious."
Donnie's stomach dropped.
Ogg floated above them, hands clasped behind his back. "One of you will remain behind to greet the turtles of the main story. Which will it be?"
The black and white turtles didn't look welcoming. They didn't look safe.
Donnie's thoughts raced. He could build a dimensional anchor. He could jury rig a portal stabilizer. If anyone could get home from this place alone, it was him. And there was no way he was letting his family be stranded in some unfamiliar, hostile dimension.
He raised his hand.
"I'll stay."
The reaction was instant.
"No, Donnie!" Raph snapped, stepping forward. "I'll go."
"Absolutely not!" Leo said, panic sharp in his voice. "We'll figure something else out-"
"Rise Donatello volunteered first!" Ogg cut in, glee flashing across his face.
He snapped his fingers.
Light exploded around Donnie.
"Wait- no! Donnie!" Leo lunged for him, fingers brushing nothing but air.
Donnie barely had time to turn before he was gone. He sent them a quick, lopsided smile anyway, meant to say I've got this, even as the world dissolved around him.
Next thing he knew he was falling.
Wind roared past his ears, his stomach climbing into his throat.
Thud.
He hit the ground hard, breath punching out of him as pain flared through his shell and limbs. "Ow."
Above him, the portal flickered once... twice... and vanished.
Silence rushed in to replace it.
Donnie pushed himself up slowly, wincing as he brushed dirt from his hands. The ground was rough and grey, scattered with jagged rocks and fine ash like soil. No plants. No buildings. No life that he could see.
He looked up.
The sky was pitch black, stretched endlessly overhead and scattered with shining stars that felt too sharp to be comforting.
"...Okay." Donnie muttered. He slid his goggles over his eyes and forced his breathing to slow. "I've got this. Everything is okay."
He turned his wrist, activating his vambrace. Static flickered across the display.
"No signal."
He pulled up his sensors next. The readout was almost entirely empty, no ambient life, no tech signatures, no energy spikes.
Nothing.
Except one small blip.
Donnie frowned and locked onto it. "Huh."
He started toward the signal, tech bo in his hand just in case. The terrain stayed the same no matter how far he walked, gray dirt, scattered stone, endless emptiness, until at last he neared the blip.
Then he saw the fire, it burned blue, low and steady, casting sharp shadows against the rocks. Sitting across from it was another mutant turtle, posture calm, swords resting nearby.
"Welcome." The other turtle spoke. "Come. Join me."
Every instinct in Donnie screamed don't.
Still, he approached and sat on the opposite side of the fire, flicking his goggles to the top of his head and keeping his bo within easy reach.
"I'm Leonardo." The stranger said.
"Donatello." He replied. "Where are we?"
"Another sector of the Battle Nexus." Leonardo answered. "I don't know what Savanti Romero is planning this time, but I suspect it has something to do with this place."
"This place how?"
Leonardo's gaze flicked briefly to Donnie. "Prolonged exposure in this dimension causes instability. Aggression. Paranoia. Madness."
Donnie stared at him. "I'm sorry- are you saying that being here is going to make us both lose our minds?"
"If we remain too long." Leonardo said evenly.
"...Great." Donnie muttered. "That's just fantastic."
Leonardo hesitated, then added. "It will also make us forget our memories. Our lives outside of here."
Donnie's head snapped up. "You mean... I'm going to forget my family? My life?"
Silence stretched between them, broken only by the soft crackle of the blue fire.
"Yes." Leonardo said at last. "If you stay long enough."
Donnie swallowed hard. His hands curled into fists without him noticing. "That's not- no. That's not acceptable."
Leonardo watched him carefully.
Donnie's chest tightened painfully. Images flashed through his mind, Leo's grin, Mikey's laughter, Raph's hugs.
"I won't let that happen." Donnie said, voice steady despite the fear creeping in. "There has to be a workaround."
"Sorry kid, we just have to hope that what ever is planned is over before that happens." Leonardo spoke.
Donnie brought his knees to his chest and wrapped his arms around them "So how long have you been here?"
Leonardo shrugged. "A day or so... I think. I've been the only one here so far."
Donnie's brow furrowed. "So far? You think more of our alternates are going to show up?"
"Most likely." Leonardo replied. "Mister Ogg enjoys a spectacle. I suspect he's planning multiple confrontations, alternate against alternate. And Savanti Romero just wants to see every version of us suffer."
Donnie exhaled slowly. "Of course they do."
The fire crackled softly between them, casting pale blue light across Leonardo's face. Donnie took the chance to really look at him. This Leonardo was older than his twin, broader through the shoulders, he looked worn, like he'd seen too much. His eyes were completely white, unsettling at first glance, but kind.
"Tell me about your family." Leonardo said.
Donnie blinked at the question, surprised, then smiled faintly.
"Well, if we're alternates, you already know the basics." He started. "I've got three brothers, Raph, Leo, and Mikey."
He nudged the fire with a thin stick he'd found on the ground next to him, watching the blue flames coil around it. "Raph's the oldest. He's been taking care of us for as long as I can remember. Loves smashing and bashing things, but underneath all that? He cares more than anyone."
Leonardo nodded once in acknowledgment.
"Then there's my Leo." Donnie continued, his smile softening. "My older twin. My other half. He jokes a lot, but he's strategic, always thinking five steps ahead, even when he pretends he's not. He messes up sometimes, sure, but he never stops trying to do right by us."
The fire crackled a little louder.
"And Mikey." Donnie said, warmth creeping into his voice. "The youngest. A talented artist and an even better chef. He's chaotic and emotional, full of razzmatazz, he shines like the sun."
Donnie looked up. "What about you?"
Leonardo leaned back slightly, eyes drifting toward the stars. "In my universe, I'm the eldest."
Donnie tilted his head. "Interesting."
Leonardo exhaled a quiet breath, almost a laugh. "Raph is next. He's aggressive. Short tempered. He charges into fights without thinking them through. But his loyalty is absolute. Once he decides you are his friend or family, nothing will pull him away."
"My Donatello." Leonardo continued. "Is the mind of our family. He'd probably lose himself over the technology you're wearing. A pacifist. Always prepared, always planning for what might go wrong. The calmest of us."
"And Mikey." Leonardo added, his voice softening. "Is endlessly energetic. Loves pranks and comics. He's extremely talented in ninjutsu, and he will tell you at least ten times that he's the Battle Nexus champion in our universe."
The two of them sat in silence for a moment, the fire the only sound in the empty sector.
Donnie let out a quiet huff of a laugh, then shook his head. He pushed himself to his feet, already typing rapidly across the holographic interface of his vambrace.
"Alright." He spoke, tone shifting into familiar focus. "I'm going to start mapping this place. If I can understand how the Nexus is structured, maybe I can figure out how to sabotage whatever this Savanti Romero is planning."
Leonardo looked up.
Donnie glanced back over his shoulder, offering a confident half smile. "I'll be back in a bit."
He turned and walked away from the fire, his footsteps crunching softly against the gray dirt. As he moved, his sensors swept the terrain, mystic energy, spatial curvature, ambient readings.
He paused after a short distance and knelt, pressing a small probe into the soil. It sank easily, humming as it activated. A moment later, data streamed back across his display.
Donnie frowned.
The readings were... layered. Traces of countless dimensional signatures tangled together, none dominant, none complete.
"...Huh."
It wasn't a single dimension at all. It read more like a dumping ground, an overlap zone where pieces of other worlds had been scraped off and discarded.
Donnie stood and kept walking.
The landscape never changed. Rocks and ash. Ash and rocks. No landmarks. No horizon. Just repetition.
And with the repetition came thoughts he didn't want.
Losing his mind.
Forgetting his family.
He shook his head sharply, as if he could physically knock the thoughts loose.
"No!" Donnie muttered. "I wont forget anything."
He slowed his pace and began to speak out loud, anchoring himself in the sound of his own voice.
"I am Donatello. I'm from New York. I like science."
A breath. "I am a softshell turtle."
His feet crunched against the ash as he kept walking.
"I have three brothers. Leonardo, he is a red eared slider. My twin. Raphael, a snapping turtle. Oldest brother. Michelangelo, ornate box turtle. Youngest."
"April O'Neil." He continued quietly. "Sister. Best friend. Human."
"Splinter, dad. Rat."
"Shelldon." His voice softened. "My AI son."
Donnie stopped walking and looked at the sky, regret settling in.
"Why did I volunteer to do this?"