Full Synopsis-: Two future geniuses fall into the other's world after a seemingly random portal appears connecting their two universes. They become fully integrated into the life they find themselves in but after time it becomes clear that they do not belong where they currently are. When Leon accidentally opens up a portal to a different world the two Donnies have a difficult decision to make, stay where they grew up or return to the universe they came from. However there's another factor at work here and it's gonna take double the turtles and double the Donnies to stop them.

Two future geniuses fall into the other's world after a seemingly random portal appears connecting their two universes. They become fully integrated into the life they find themselves in but after time it becomes clear that they do not belong where they currently are. When Leon accidentally opens up a portal to a different world the two Donnies have a difficult decision to make, stay where they grew up or return to the universe they came from. However there's another factor at work here and it's gonna take double the turtles and double the Donnies to stop them.

Some might say that things happen for a reason and there are others that believe random events are just that, random with no explanation no matter how much thought one might put behind it. When a small blue portal appeared, linking entirely different universes in the lairs of two identical but vastly different families it was unclear if it was deliberate or accidental.

A perfectly round glowing circle, crackling with energy swirled into existence, a window, a doorway in between worlds just big enough for two curious infants to fit through. Their bright eyes shone as they approached this wondrous glowing thing, their brilliant growing little minds taking in every detail as their brothers played a little ways behind them, oblivious to the illuminated spectacle.

They both knelt back on their haunches tilting heads as they caught eyes with the other. It wasn't a mirror because they in no way looked the same. One cooed in fascination while the other chirped in wonder. They lifted hands and pressed it against the portal fully expecting it to be solid, to give resistance but instead and to both tots surprise their hands connected, one flat palm against the other. They gasped. Their eyes caught again and after a moment's pause they smiled and giggled as they began chirping at each other. This was amazing!

Hamato Yoshi had briefly left the room, heading to the makeshift kitchen that he was still attempting to put together. He worked during the night whilst his unruly little brood slept and spent most of his day time hours with his adopted sons not far from his side. They had been in this new home for 10 months and although safe, the giant rat was still getting used to the lair that his little ones had bore him too after the fateful encounter with those strange creatures above. He was still careful, still cautious, his new family was precious to him and he would do anything to keep them safe.

He wandered back into the main living area (he never liked leaving his sons alone for too long) and smiled to himself as he heard them giggle and chirp as they played on the rug. He climbed into the sunken lounge area setting the tray of tea and pot down when his ears twitched, detecting a fifth chirp. He'd learnt to tell his boys vocal ranges apart and each of their tones were quite distinct to him now, so where did that other chirp come from?

Yoshi frowned as he also realised that one of his four tots was absent from the group playing in front of him. Where was Donatello? He could hear him but where was he? His large ears swiveled and he twisted around pinpointing the gleeful chirps coming a short distance behind him. His heart rate calmed slightly and he climbed back out to fetch his errant child. The curiosity of that little one, he was always figuring out how things worked, always investigating anything and everything that he brought into the lair. A real smart child indeed, however it did mean Yoshi had to pay close attention whenever he brought supplies and materials home because Donatello kept delving in and helping himself to see what they did.

As he followed his ears his sense of smell suddenly twitched and a tension twisted in his chest. He hurried forward and fell short of the sight before him. There was Donatello but it was what was in front of him that alarmed the new father. A swirling blue circle of energy fizzled and cracked and what looked like a mirror was displayed in the centre with another baby turtle standing on the other side.

Their hands were touching, palms flat as the two different infants chirped to the other. What was this?! A doorway? To where? The other baby was so different in looks that it was hard for his mind to process. It also solved the mystery of the new chirp.

There was nothing immediately dangerous about the situation, just two children engaging with one another but his anxiety rose when he noticed that the 'window' was shrinking.

Yoshi's heart clenched. "Donatello! Come away from there! Now!"

Donatello looked over his shoulder, his unsteady little legs wobbling as he wasn't entirely confident with walking just yet. He smiled and chirped back, oblivious to the danger. His fingers were now interlaced with the other child's as he seemed to be steading Donatello's balance out of possible instinct perhaps? The angular and lithe little one seemed a lot more competent on his feet.

"Purple! Stop! What are you doing?"

Yoshi frowned as a familiar voice but not so much so emitted from the other side of the glowing window. A Japanese accent that he was obviously very familiar with.

However the other voice seemed to startle the other child who jolted back inadvertently pulling Donatello through the window. For a split second they collided and lost their balance and Yoshi's heart almost stopped as the babes fell-

- in opposite directions.

Each released a squeak of alarm and Yoshi darted forward as the window continued shrinking. "Donatello!" He caught the other child as his own fell through the other side.

"Purple!"

It was then that Yoshi saw the owner of the voice. It was a rat but quite obviously a man too. A mutant like himself. A familiar symbol was emblazoned on his kimono... Their eyes locked as they stared at the other desperately, the window now far too small to fit either child to the other side. And in that moment Yoshi knew instinctively that he was looking at another version of himself. A new father trying to protect his children, just like him.

"I am sorry," Yoshi found himself saying, reaching out a claw to the other rat man and Donatello.

His other self reciprocated and both children too. Each touched the fingers of their respective parents looking worried and confused.

Both on hands and knees the window shrunk more and Yoshi clasped his other self's child to his chest as he wriggled, giving his counterpart an unspoken but empathic look. "I will look after him," he murmured, his breast so tight that it threatened to overwhelm him.

There was a pause and the desperate and helpless look of his other self only intensified. He pulled Donatello to his own chest as the tot chirped and strained to reach back for his true father. "I will too," his voice wobbled and Yoshi instantly sympathized with him. The poor rat man seemed terrified, he was too but what could either of them do? The window would close in mere seconds and they each had the other's son.

They had to trust each other. Each seemed to take a summoning breath as they finally looked back at the other with reluctant acceptance. They would raise the child as their own until hopefully a solution to this awful predicament revealed itself to them. Yoshi nodded and his other self mirrored him.

Another second of silence and the other rat man suddenly saw fit to cry out. "I call him Purple!" As the window shrank to the size of a baseball.

Yoshi frowned slightly, seeing a flash of purple on the skin of the infant in his arms. He nodded toward his own, "Donatello," he affirmed with a second nod.

The children in question looked in confusion at their fathers on the other side of the shrinking window, squeaking and chirping in alarm, reaching out in desperation when the window fizzled and snapped, vanishing from existence.

The pressure on Yoshi's breast increased and for a moment he couldn't breathe. A loud siren seemed to fill his ears as he swayed on the spot and fell onto his haunches, momentarily forgetting the child that he currently held.

The tugging and squealing persisted and the rat pulled his senses back as the infant made his presence known.

"Yame! Stop, little one!"

'Purple' as his other self had called him, persisted going so much as to bite him.

Yoshi hissed under his breath. "Yame! Stop!"

He never meant to raise his voice but it did the trick. Purple stopped squirming and stared up at him, his dark eyes full and wide, looking fearful more than anything else.

Yoshi bit his tongue guiltily as he looked down at this uniquely formed child. "I'm sorry kodomo," he hushed. "But you needn't be scared."

Purple wriggled again, snatching at his kimono and pulling himself more upright. He pointed to where the window had been, then clasped his hands together before pulling them apart and tapped Yoshi's chest pointing back to the absent window again.

The rat raised his eyebrows. It appeared that this little one was just as bright as his own. It felt like he was using some sort of sign language. It took a moment but when Purple repeated the actions the father immediately understood what he wanted.

Yoshi creased his brow guiltily. He shook his head sadly. "No kodomo, I'm sorry, I don't know how to open the window again."

Purple bit his lip, and raised little fists to his face. The breath seemed to judder in his chest as his softly angular face creased in what Yoshi could only call anguish. It broke his heart. The boy wanted his father and knew he was stuck. There wasn't anything that Yoshi could do, at least at the present time. "Don't worry kodomo, you're safe here until we can get you back home, yes?" He didn't know if Purple could understand him.

Soft, sorrowful little mewling sounds escaped the boy's throat and Yoshi cradled the sobbing babe up against his shoulder. "I'm sorry Donatello," he uttered, he didn't feel right calling him Purple because if he was an alternate version of his own son that's exactly who he was. He was certain, so that was what he would call him.

A little head buried itself into his neck, strong reaching arms clinging to him desperately as the whimpering continued. "It's okay kodomo," Yoshi whispered, feeling an unwanted mass begin to breach at the back of his throat. "Chichi's here, papa's got you," and a rogue tear tumbled down his cheek.

I know... it's been too long since I posted or updated anything on here but I wanted to try and rectify that. This story is already on AO3 and WattPad and for those of you who don't follow those I wanted to share my newer content from there here. :)

I'm rather proud of this story thus far and I hope you all do to here! :D

See you all soon dear readers!