Chapter Text
Leo was up there.
That was the first thought that went through Donnie’s head as he stared up at the giant gaping maw in reality, the one leading to the prison dimension, the one that was going to destroy the world. Leo, the brother of smiles and jokes and never taking anything seriously. The brother of annoying grins who had that small, hidden vulnerable side he barely showed.
The brother who would do anything for his family.
Leo was Donnie’s twin, Donnie’s other half. There wasn’t one without the other. Since forever, they had done everything together. Whenever one was feeling down, the other would help them just as well as if one was mad, the other would annoy them further. Donnie couldn’t imagine a life without Leo and Leo couldn’t bear to live in a life without Donnie. And Leo was about to go through that portal with a murderous Kraang that had already decimated the planet years in the future.
Leo was going to die. It was a fact, it was the answer to the equation and the solution to the problem.
Donnie loved being right. He loved rubbing the truth in his dum-dum brother’s faces.
Not this time.
He heard Raph pleading to Leo over the wrist com, but he knew his twin. His stupid, stubborn twin that had always been the difficult one. He wasn’t going to listen, he wasn’t going to back down, he knew what he had to do and he was doing it.
And all Donnie could think of was; no. Not Leo.
“When I get over there, you close that portal,” Leo was saying, his voice determined with a little tremor beneath it.
“Don’t you dare, Leo,” Raph ordered, his voice shaking, tears gathering beneath his eyes, one gummy and squinted from the Kraang parasite digging into it.
Leo would dare. Donnie knew that he would.
Before Donnie knew what he was doing, he was already in the air, using his battle shell as a jetpack to blast himself up towards the Kraang ship where his brother was. It was some sort of desperation that was deep inside of him, some sort of need for his brother, some sort of brotherly feeling that couldn’t be stopped.
“DONNIE!” he heard Raph yell below him, and then his older brother's voice came on over his wrist com, getting louder and louder in panic.
“Donnie, where are you going?!” Raph shrieked desperately.
Donnie shut it off, gritting his teeth in sheer determination, landing on floating chunks of debris, running along them before launching himself into the air again and taking off towards his brother. As he got closer, he saw the air start to flash with blue, and he watched the forms of Leo and Kraang prime battling. Leo didn’t jab any comments or remarks at the Kraang this time, just zipped around and dodged with a determined silence, so unlike the annoying, cocky brother Donnie knew so well. Leo came out of a portal, rearing back and throwing one of his swords past the Kraang and into the prison dimension behind it. The alien dodged and then charged forward, batting Leo out of the air like a cat and slamming him into the technodrome beneath and making the slider let out a grunt of pain.
Donnie put on one last burst of speed, the noise of his brother being hurt fueling him until he landed on the rock and pulled his bo-staff out, gathering the last recesses of his ninpo and flinging purple rockets at the Kraang. They slammed into its side and the mech-clad alien turned around, staring at Donnie with its beaming red light. Leo was flat on his back, inhaling shakily under the Kraang’s claw, his teeth clenched in a wince. Donnie saw blood spotting the Kraang’s claws above him. He looked up at met eyes with Donnie, his eyes widening and an expression of horror crossing his face.
“You?!” The Kraang snarled, turning to face Donnie but keeping a foot on Leo. “What are you doing here?”
“Making sure my absolute shitass brother doesn’t do anything stupid,” Donnie spat at the alien, spinning his bo staff once.
“Donnie….” Leo’s voice drifted from him, and Donnie saw him struggling beneath the Kraang’s talon, clawing at it with his hands as he tried to wiggle out. The Kraang tightened its claws around him with a snarl and Leo let out a whine of pain. A burst of anger shot through Donnie.
“Leave him alone!” the softshell cried, lifting his bo-staff and firing more rockets at the Kraang. The alien blanched, stepping off of Leo and away from Donnie’s attack, putting its arms above its head to block the attack. Donnie stopped, feeling exhausted as he used the last of his ninpo.
Leo stood up shakily, coughing and clutching his side, which was spotted with blood. He hacked onto the ground, and Donnie saw blood fall.
“Get down there!” Donnie cried at Leo, flinging an arm to point at the ground below. “Get out of here!”
“What? No!” Leo protested. “What are you doing here? You're supposed to be– you're supposed to be safe!”
“And let you kill yourself?” Donnie spat, making Leo wince. Yea, that’s right, you’re not slick, ‘Nardo. “Not likely. We’re both getting out of here alive.”
“NONE of you are getting out of here alive!” Kraang roared, recovering from Donnie’s attack and launching himself at them. Donnie dove to the side and then ran over to the Kraang, leaping onto its back and holding onto its mech suit. It yelled, stumbling backwards and trying to claw at the turtle on top of it, but Donnie held on relentlessly. Leo, now with only one sword, used it to portal to the side and stab the katana into the Kraang’s heel.
“Donnie, get out of here!” Leo screamed, the longing in his voice breaking Donnie’s heart. The slider looked up at Donnie, his eyes pleading.
He wasn’t going to let Leo go through that portal. No way. He wasn’t going to let his twin do something like that to himself.
Donnie swore that to himself. Leo had a point, there could only be one way to keep the Kraang in there, and that was to lure it in.
But Leo wouldn’t be the one to do it.
Donnie leapt off of the Kraang and down to where Leo was, and he saw the slider’s face relax and something as sick as a smile split it.
Donnie only had a few seconds to think, because he could see Leo’s ninpo powering up as he gripped the katana stabbed into the Kraang’s foot, getting ready to shoot himself and the alien into the prison dimension.
But Donnie’s brain knew the only thing that would work. It was such a stupid idea. So stupid. But Leo would be alive.
That’s all that mattered.
Donnie leapt and grabbed onto Leo as all three of them were shot into the prison dimension. Leo let out a surprised yelp as the weight caused him to let go of the Kraang. The alien reached down and wrenched the sword out of its heel, flinging it away before turning to the two turtles with hatred in its lemon-yellow eyes.
“No, no, no, no,” Leo repeated, pushing Donnie away and staring at the turtle in the zero gravity they were in, caused by the portal being opened. “What are you doing?!”
Donnie reached up to his battle shell and pressed the release button, pushing it onto Leo at the same time that he activated the ejection option.
“Something I’m not sorry for.” Donnie said, before Leo was taken out of the prison dimension by Donnie’s battle shell and onto the safety of the other side.
Leo landed somewhat roughly on the ground, and then Donnie pressed his wrist tech, watching arms on his battle shell shoot out and pin Leo down. Where he was safe. Where he wouldn’t die, he would be safe, he would be okay. And it would be up to Donnie to make sure the Kraang didn’t escape.
He tapped his wrist com and screamed into it, “CLOSE THE PORTAL NOW!”
Several voices shrieked back at him, Raph, Mikey, Leo, in the safety of the shell, his voice cracking in desperation. All of them realized that Donnie was in there, Donnie was going to be trapped, Donnie was going to die, and Leo was going to live.
But it was too late. Casey had done his job well, he had kept his word, despite everyone begging him not to. With a huge surge of air and an earsplitting BOOM, Donnie and the Kraang were both shoved backwards, spiraling through the air deeper into the dark expanse of space. Donnie pinwheeled through the air, everything blurring past him, nothing making sense as he spun on and on, flailing out with arms and legs until he slammed into rock with a yell of pain, cracking his head against it and his unprotected shell already bleeding. He sat there for a moment, gripping his head where dizziness was whipping through his body.
When he looked up, he no longer saw the entrance to the portal, with New York behind it and Leo tangled in the battle shell, his horrified face staring after Donnie as he disappeared. There was nothing but air, darkness, floating rocks, and a murderous Kraang. Donnie never thought in a million years that he’d make such a stupid decision and throw away everything like he just had. But he did.
Standing there, his head spinning and his lungs struggling to grip the air and draw it into his body, he started to feel panic as the reality set in, terror at the thought of being alone, of dying alone, of never seeing his family again. The thought of being hurt, of pain, of what was surely going to come in the future, and Donnie’s chest restricted, his eyes going wide and tears pricking the edges of them.
And the factor that altered the equation entirely;
Donnie was in the prison dimension.
And Leo wasn’t.