Chapter Text
Watching Peter Parker stumble and fall toward him, crying out for help while he turned to dust wasn’t something Tony ever imagined would happen. He’d pictured several futures for himself ever since he ended up in a cave with a battery strapped to his chest—most of them involving dying—and after New York, his imagination ran even further amok. It had occurred to Tony that Peter might die which is why he never wanted him to follow him up to space in the first place, but being reduced to dust wasn’t exactly what Tony’d had in mind for the boy. Now that it had happened, Tony’s only goal was fixing it.
Dr. Strange had told Tony about their terrible odds where beating Thanos was concerned, but that didn’t deter him. So, the doctor had given up the Time Stone and disappeared. Tony had done more with less. He could find a way to reverse what Thanos had done without some rock he hadn’t even known existed until recently.
Whether the Avengers won or lost the fight against the big, purple fuck, Tony had figured it would come at great cost. He hadn’t realized just what that cost was until he’d lost Peter. A broken suit and being trapped in outer space were the least of his worries. Peter was gone. Dead, erased, dust. The specifics weren’t very important to Tony. All he knew was that he was covered in ashes and bleeding profusely from his chest. What else was new?
The kid he’d recruited at 14 to help him fight his own friends, the one who’d wormed his way into a broken, old man’s heart, and who’d only just gotten Tony to admit his feelings. A lot of good it had done because Tony had told Peter he loved him back just in time to lose him. Just typical. Tony had his regrets, but he couldn’t feel too guilty about any of it since Peter loved him. Whether it was right or wrong to bring a teenager into such a big fight was an old worry. Right or wrong wasn’t the issue anymore. Tony just knew he had to fix it, or at least change it, or improve the outcome. Whether it meant dying himself, or fucking up the timeline, or pissing off the rest of the Avengers, he didn’t care.
Regardless of what Strange had to say about anything, Tony now knew that time travel existed, or at least that time-altering dynamics did. All that told Tony was that whether he had access to the Time Stone, or not, it was possible to do something because the very fabric of the universe allowed it. He only had to tap into a bit of his genius, and combined with some quantum physics, he might have a chance at getting everything he’d lost back. Peter.
Okay, so maybe being trapped in outer space was more of a concern than he’d initially thought. Nebula wasn’t so bad. If he was going to be trapped with anyone, he was glad it was with someone who had a brain, even if it was full of mean thoughts.
When Tony left one last message in his destroyed helmet, he addressed it to Peter, although he knew that the boy would never get to hear it unless the rest of the Avengers figured out a solution to the Snap without him. He doubted that even though he didn’t want to.
When I drift off, I’ll think of you.
Meeting Captain Marvel and making a grand entrance on his own lawn might’ve made him smile once, but he didn’t have any smiles left to give. He had been on the verge of death in a floating piece of scrap metal, starved for water, food, and air. He’d been prepared to quietly slip away into death. Not that he’d given up, just that there was no fight left. Nothing he could do except wait to die and hope that some sort of afterlife might reunite him with Peter, but maybe the Snap had erased everyone’s existence so completely that they wouldn’t qualify for any sort of afterlife since they’d technically never lived.
Too much to think about when he was dehydrated and dying.
His first words when he reunited with the team—some friends, some more like family, some nothing—were, “I lost the kid”. Everyone knew who he meant, but only a couple of his welcoming party knew what it meant.
His return felt more anticlimactic than he’d imagined it being since the only ones there to receive him were a broken crowd of Avengers, and they were still the losers of the fight.
Being stuck in space, and then being stuck in bed wasn’t ideal for achieving his goal. He needed to get back in the lab, start working on something, anything. He needed to upgrade E.D.I.T.H. first of all, repair his suit, create another one for Peter, and get F.R.I.D.A.Y. back online. Also try and get Karen back for Peter because he’d want her when he returned…
Tony wasn’t in any physical pain anymore. His anguish was mental. He couldn’t figure out what to do first or at all. His priorities were scrambled and skewed within his brain.
Tracking down Thanos to steal back the Stones was a dead end which Tony might’ve anticipated if he hadn’t been bed ridden and excluded from the plan. If he could somehow manage to fix what had happened whether it meant time travel with the Time Stone or without it—after the Avengers were too late to find Thanos before he destroyed the gauntlet, he could at least be sure he’d be doing it without it. That was somewhat comforting since it was one less variable in the equation. Plus, Thanos was dead which made it slightly easier to breathe.
After he put some weight back on and settled everything around the compound, his priorities became clearer. He had no leads to work with. His delirious and desperate mind had cited time travel as an option, but he had nothing else to supplement the grandiose idea. Time travel how? Where? When? To do what? When Strange had said there was only one future where they won, what did that mean for the past, and what would winning look like? If they somehow got a second shot at fighting Thanos, how would they know they’d won? Tony felt sick when he wondered if this was what Strange had meant—maybe the universe remaining halved and Thanos being dead was the win. Tony refused to believe it.
Before Tony could even think about logistics like how far back he had to go—how old was Thanos, anyway?—he had to develop a suit suitable for time and space travel and with an AI that could function anywhere anytime. He’d been able to fight Thanos without F.R.I.D.A.Y., but it hadn’t been ideal.
He didn’t know the complete parameters of the potential suit design. Obviously, he needed to be able to breathe in different atmospheres because during any given time in Thanos’ world-conquering past, he was on planets that weren’t Earth. He was going to have to build the mack daddy of suits. That would take…at least a month, and that was without sleeping. Tony didn’t like putting more distance in between him and his goal of getting Peter back, but it was necessary. If he was going to do it, he had to do it right, and if he got killed, nobody would be able to finish his work, so despite how much it pissed him off, he had to take precautions and be careful.
If people had thought he was a workaholic before, a shut-in who never left his lab, they hadn’t seen anything yet. Tony didn’t leave his workspace for anything.
The number of Marks for Iron Man suits skyrocketed into the hundreds. He worked on just as many for Peter which earned him nothing but sympathetic looks from Happy, Rhodey, and Pepper. They didn’t dare tell him he was wasting his time, though. They would’ve been wasting their breath.
When Scott Lang showed up at the compound, Tony didn’t even bother coming up to see what all the fuss was about. It was Rhodey who came down to him to explain that Scott had useful information for the team.
Bingo.
Tony’s first lead.
Rhodey gave Tony his second lead when he made a joke about wrapping a cord around baby Thanos’ neck.
The rest of the team was quick to chide Rhodey, but Tony knew what a solved equation looked like when he saw it. It would be perfect. He could roast that shriveled grape of a creature into next week before he even left the maternity ward—not only would he cancel out the Snap, but no planet, or world, or person would ever be conquered by the monster. Plus, he would be easier to kill when he wasn’t so large.
Although it seemed to be the solution for everything wrong in the world, it presented a dilemma to Tony which made him think on it some more. If he could somehow get time travel to work, and if he went back and killed Thanos, depending on when he did it, the outcomes would look drastically different. As far as he could theorize.
If he went back in time to when he’d been stealing back the gauntlet with Peter and the Guardians at his side, they could win there, but if it hadn’t worked then, Tony didn’t see what good returning to that moment would do. Strange came to his mind again. He was getting tired of thinking about the guy. The man had said only there was only one way to win the war, so wasn’t it pointless to go back and retry things they’d already done?
Even Tony felt confused. He was too close to the project, and he could sense a breakthrough, but every question he answered, and every theory he cooked up was just met with more questions, and more possibilities of failure.
Tony considered going back in time just enough to warn Thor about the impending attack on his ship, but if Thor, Loki, and Hulk hadn’t been enough to thwart Thanos, then he didn’t think warning them would do much good.
His head was starting to feel the way Strange had looked when he’d gone all squirrelly on Titan while he imagined all the possible futures.
Tony would have to pick a time and place that was definite, and it was clear that he was going to have to do it before Thanos got too big or retrieved any of the Stones. Which only meant one thing because trying to travel to any other point in time along Thanos' life was too difficult to nail down. Thor was over a thousand years old, so why not this asshole? Oh yeah, what was Thanos up to in 1409, 1777, 1965? He could’ve been fucking anywhere. Probably creating the Black Plague or just casually murdering. Both?
Maybe it was the desperation and his debilitating migraines more than critical thinking, but Tony eventually came to the conclusion that Rhodey’s joke had been the complete answer, not just a lead. He would go back and kill Thanos when he was a baby.
For Tony to learn the most important things about Thanos, namely his birthday and exact birthplace, he had to rely on Thor, and it was lucky that the god had drunk himself into delirium because he gave up everything he knew without even caring to ask why or spill the beans that Tony had been asking anything at all.
It didn’t sit well with him that going back so far in the timeline meant a much greater deal of history changing drastically. If he had to go back hundreds of years to stop Thanos, then the ripple effect of that change would affect hundreds of years of history. If his starting point was 2018 in the basement of Avengers Compound, and his ending point was Titan one thousand years ago, it was possible that he would cut off the entire timeline, not just alter it. If that happened, there would be no basement to return to, and he would cease to exist. That was a problem.
If he somehow managed to kill Thanos and travel back to 2018, it would also be possible that everyone who’d been snapped away would be back and that would be the only change. Tony liked that idea best.
His mind swirled with possibilities. Creating doubles of people if the timelines merged. Some people never existing in the first place. Stopping Thanos only for something worse to take his place. Stopping Thanos as a child, but it having no bearing on the future.
What ended up fully convincing him to go it alone and to stick with the plan of attacking the genocidal maniac while he was fresh out of the womb was that if the plan worked, not only would the Snap be avoided, but every terrible thing Thanos had ever done would’ve never happened. Half the universe would come back to life, and the thousands that Thanos had killed even before that would be alive as well.
There was always the failsafe that if time travelling worked the way he thought it would, if he fucked it up, he could just keep travelling to different points in time and trying again until something stuck.
Tony made a big spectacle of explaining why time travel wouldn’t work regardless of what Lang thought he knew to keep them off his trail. Tony threw the man’s Back to the Future references back in his face as if that wasn’t exactly right. All the while, he was formulating his own plan. Even Bruce took his carefully cited references and theories and ran with them in another direction. Tony almost felt bad for duping his friends, but he wanted to do this alone.
If there was a chance that the mission could go sideways, or that an altered timeline could do damage, he didn’t want to be stopped. Maybe he should’ve learned from his mistake with Ultron and sneaking around the team’s back, but oh well. He didn’t want his plan to fail and have to return to the present day, humiliated. And if it did work, Tony didn’t want to think about anything beyond that. It had to work. End of story.
Tony had run all the data a million times, and without all the variables, it was impossible to nail it down for sure, but the odds of his success were better than Strange’s. That was all he could ask for. If Peter got to be alive in any capacity, Tony would take it. It would just have to be okay that Tony might not get to be alive with him if he didn’t make it, or if changing the timeline erased him from existence, or if some alternate Tony with no memory of this was the one to make it out of this shitstorm.
Tony left a virtual message for the team before he left just in case he didn’t succeed or return, or both.
Going back nearly a thousand years into the past might’ve been cool under different circumstances, but to Tony it was nightmarish. He’d taken several calculated risks even attempting this plan, and several other incalculable risks, but when he approached the young Titan, prepared to strike, it really hit him how fucked up the plan was. If he killed Thanos, and the course of the world changed immeasurably, Tony wasn’t even sure if his time-travelling apparatus would be ready to receive him back in his present.
Those were the thoughts that plagued Tony’s mind when he approached the child, not the questionable morality of the whole thing. He was about to kill a kid, but Thanos had killed several. The quote about one death being a tragedy and millions being a statistic came to mind. Tony had killed before and didn’t lose sleep over it—that was a lie, he lost lots of sleep, but it didn’t make him regret it.
As far as Tony was concerned, Thanos was toast just for murdering Peter. Avenging trillions was a bonus.
After it was done, Tony took a moment to feel any satisfaction that might be coming his way, but all he could feel was a strange buzzing throughout his entire body. His suit wasn’t electrocuting him according to F.R.I.D.A.Y., and the time device affixed to him wasn’t actively transporting him back to where and when he’d come from. It felt simultaneously spiritual and physical, like his entire soul was being tugged in every direction.