Work Text:
Donnie's shift had ended half an hour ago, but he hadn't left his computer chair. Elsewhere in the lair, voices only partially muffled in their open-concept home, Leo and Raph were shouting at each other. The specifics didn't matter. It was a day ending in "Y" and there was no escape from angry yelling even after he took off his headset.
He was glad Leo had returned, that Leo was home now.
That Leo hadn't died alone far away from his family.
But.
When Leo left home there had been promises and unspoken understandings. Donnie being in charge of the team was supposed to be temporary, with a set expiration date for shouldering both his own responsibilities and Leo's.
The first year without Leo had been difficult, but there had been an end in sight. Donnie could get through it because he knew it would eventually end. He could make it through a year of doubled responsibilities, of Master Splinter comparing him to Leo and finding him wanting, of Raph's resentment and antagonism, of Mikey's rapidly-growing anxiety and depression.
Eventually the year would end and Leo would be home and everything would get better.
He could finally shed some of the weight he was holding up, relax a little, and be himself again instead of a subpar Leonardo substitute.
But then the year ended and Leo didn't return.
There were no more letters from him, no sign that their missing brother was still alive. Master Splinter claimed he was, that he could still sense Leo's living spirit.
Donnie hadn't been able to tell if their father was trying to fool them or himself. Or if he really could sense Leo, alive and just choosing not to come home.
Either way, Leo hadn't come home. He…might never come home.
So Donnie had mourned. Both the loss of his brother and the loss of his own peace of mind.
He had mourned the end that had vanished from sight. He had mourned the new status quo he was stuck with.
Then he had packed up all his thoughts and emotions on the matter and buried them down deep, and got on with his life. He had set up algorithms to scan the news for signs of his brother's body, in case they had to go steal him from a lab.
Or maybe it would just be Donnie breaking into a lab to steal a corpse. He didn't think he could put Mikey through that, and god knows Raph wouldn't even listen to him long enough to learn why he wanted to break into a lab.
Just in case, Donnie had researched and learned the fastest and easiest ways to dispose of a body without leaving evidence. He had wondered if Leo ever felt sick to his stomach knowing he might have to do something so distasteful to keep their family safe. He had wondered if Leo ever considered doing anything like corpse-desecration to protect the family, or if Donnie was alone in that.
Would Leo's honor have allowed it?
Did Donnie care about honor, if it meant his family was safe?
The second year had been harder.
With no end in sight, no one to lessen his burden, Donnie had…survived.
Raph had been a lost cause, almost as absent as Leo and twice as violent as usual when he did make brief appearances in their lives.
Master Splinter had been more obvious than ever before in his favoritism of Leo, unwilling to put in more than a token effort in being there for his remaining sons.
Mikey…
Mikey had been clingy.
Mikey had been needy.
Mikey had been the only one Donnie could count on for anything.
There had been days when it felt like only the two of them were left of their once close-knit family.
So Donnie had made it through the day for Mikey's sake more than his own. Which probably wasn't healthy, but it had gotten him through the endless days.
Days full of an absent father and violent brother at home, and Schrödinger's brother in a South American box.
For Mikey's sake, Donnie would tread water instead of drowning. For as long as he could.
For a second, hopeless year, Donnie stomped down his feelings about it all and got through the day. And the next day. And the day after that.
Then Leo returned.
Just showed up one day like he had never left.
The dual rushes of relief and resentment had almost made him dizzy. But Donnie had done what he was good at after two years of practice, and buried any negative feelings until he could smile and welcome his brother home.
He hadn't told Leo about the algorithms he quietly shut down. Or his struggles, with both honor and duty. Or the plans that still lived in his head for how to sneak into a lab.
Donnie hadn't looked Leo in the eye and said "I learned how to dispose of a body for you."
He wanted to, though.
Instead, he bit down on the words, swallowed his emotions, and got through another day.
And Donnie had been more than willing to relinquish the burdens of leadership that he had never truly been allowed to fulfill.
Though Leo…hadn't quite picked it back up. He had tried, he had definitely made the effort. But…
Leo's reintegration into the family had been…rocky. Their long-absent brother didn't seem to realize that life had continued while he was gone. The rest of the family hadn't been frozen in stasis awaiting his return so he could seamlessly slide back into his old role. They weren't a coat he could take off and put back on at his leisure.
So leadership entered a sort of limbo state where technically Leo was leader again but no one was really following him.
Donnie still found himself responsible for the household, since Leo didn't know how things worked anymore. And because Master Splinter had forbidden them from missions while Leo was gone, that was the only part of leadership Donnie had ever had.
Leo was back, but nothing actually changed. Except it was more awkward and Splinter expected them to defer to Leo on things their brother knew nothing about. The tension between Leo and Raph had returned, even worse than before Leo left.
Then they had managed to pull together long enough to fight a bad guy and save the day.
After that things were better.
For a while.
Then whatever peace had been reached between Leo and Raph wore away and they started butting heads again.
And again, and again, and again.
The brief stirring of hope that things would be better now that Leo was back had died just as swiftly as it had at the end of the first year he was gone.
Donnie was back to treading water again, but…
Drowning didn't sound half bad, these days.
He winced as Raph's voice rose to a volume and pitch nearly identical to that of an irate customer Donnie had spent over an hour on the phone with earlier. There was no escaping it. He would never be free of the yelling, the fighting, the responsibility.
A riptide of emotions momentarily pulled him under, surrounding and suffocating him. Hope had already been snuffed out, but now it was replaced with the sinking dread that Leo's return was only making things worse.
It wasn't getting better.
It never would.
And no amount of stifling himself would ever make it better.
No end in sight unless he made one...
Donnie was idly looking up how tall the George Washington Bridge was when he heard a tentative knock from behind him. Looking away from the screen, he saw Mikey huddled near the entrance to his work space. Mikey flashed him a nervous grin and hunched his shoulders, head tilted in a question that wouldn't be voiced.
Rather than acknowledge that they were both hiding from the fight happening elsewhere in their home, Donnie leaned over to hook a foot around the base of the second computer chair he had started keeping in there for Mikey. Usually it was tucked out of the way, but if it was out then it was a clear invitation.
Mikey's grin became a bit more genuine as he bounced into the alcove and plopped into the chair, letting it spin a few times before rolling closer to Donnie.
"Sooo," Mikey started, then they both winced at a sudden crash from the direction Leo and Raph had been fighting in. Mikey hunched in on himself and stared down at his knees.
"You wanna watch cat videos?" Donnie offered, opening a new window and scrolling through his bookmarks.
"Desperately, bro," Mikey breathed, slumping in relief.
Donnie chuckled and pulled up a recent favorite. While they tried to drown out the sounds of their brothers fighting with the much more lighthearted sounds of a cat playing the piano, Mikey pushed his chair right up against Donnie's.
"It'll get better...right?" he asked tremulously, leaning his head against Donnie's shoulder.
Closing his eyes and mustering up enough of a smile for it to be heard in his voice, Donnie rested his head against Mikey's and replied, "Yeah, of course. We'll make it through this, we always do."
"Promise?"
And Donnie, who had no intention of even making it through the week, held his brother close while he still could and lied through his teeth. "I promise."