I think by reading the description, people can tell what this is gonna be. You see, you think you'll stick with only a fandom or two, but then a movie like Endgame comes out and you just have to go "nope, must fix."

So I'm doing probably the most cliché fix-it ever: the time travel, change the past to ensure a better future fix-it, and I'm well aware there are already fics out there where the Stones send someone (mostly Tony) back in time to change the outcome of the Infinity War and the Decimation.

However, hopefully I am the first to write a story where it's Tony and Natasha going back to rewrite the past, and hopefully I am also the first to write a story with them racing to do what you'll find out in this prologue.

So I'll let you read the prologue and get back to you at the end to explain what's happening!

Disclaimer: I do not own Tony Stark, Natasha Romanoff, or anything recognizable from Marvel. They are owned by their respective creators and Marvel Comics.

"We're gonna be OK. You can rest now."

For some reason, those were all the words he had needed to hear before he felt himself die. Just that reassurance that all he had done to bring everyone back had paid off for the better. Everyone who had been dusted, from the Spiderling to the Bleeker Street Wizard to Quill's band of merry Guardians, had returned from their dusting, and Thanos and his army of aliens that would have obliterated them had been dusted in return. If that meant everyone he cared about and loved would be safe, then that was worth the snap he made.

"We agree. Well done, Anthony Stark."

With a startled shout he should not have been able to make, Tony Stark's eyes snapped open, and the brilliant orange light that shone around him made him instantly close them once again. Just as instantly, he came to two conclusions. One . . . there was no way he should have been able to shout when he was dead as a doornail.

And two . . . he wasn't really sure, but he was pretty confident the afterlife wasn't orange.

He cautiously opened his eyes again, slowly turning on the spot. Sloshing made him look down, and he realized he was toe-deep in water that reflected the same orange of the sky. He lifted his foot and blinked when he saw water roll off his shoe like he was waterproof.

That was the other thing that surprised him. He was no longer wearing his Iron Man armor; instead, he was in dark jeans, motor boots, and a black track jacket, almost similar to what he had worn during the Time Heist. How the hell had he somehow woken up in an afterlife with an orange sky, water floor, in clothes he hadn't been wearing before? "What the hell?" he finally muttered.

"Not quite, Anthony."

His head shot up at the female voice, clear as bells, and he looked around, squinting into the orange sky. "Who's speaking?" he demanded, mind flashing back to when Scott Lang had disabled his suit in Leipzig.

A snort came from nowhere, followed by an annoyed, male baritone voice. "For the smartest among the mortals, he is quite slow."

"Keep in mind, brother." This male voice was older, and sounded slightly amused. "Even my bearer was the same when he first came into his powers."

"And the one I was joined with never truly understood how to use me." That was another male voice, the youngest of the three, with an accent Tony recognized. "When faced with what is not understood, it takes time to comprehend."

Another snort from the first voice. "Do not even remark on that, brother."

"Me?" the second voice asked, definitely sounding amused this time. "I would never."

"On the topic of understanding," a female voice cut in this time, a sultry alto tone. "The one who attempted to utilize me faced consequences beyond his understanding."

"Who had the worst consequences, sister?" the female, bell-like voice asked. "You banished him to watch over me."

"Yet he could never reach you, sister. He had to watch while others sought you."

The bell-like voice sighed. "Yet he was pleased to send sacrifices to their deaths. That was not a consequence for him after all he had done."

Tony's mind was spinning a mile a minute, and he finally pinched the bridge of his nose. "I'm hearing voices in my head," he announced. "I'm going insane."

There was a moment of silence, then the bell-like voice finally spoke again. "No, you are not going insane, Anthony. On the contrary . . . you have never been insane at all."

"Some people may disagree," Tony mumbled.

The accented male voice hummed in disapproval. "Then that is their problem, not yours."

"Brother, that is not what he is here for," the eldest male voice reprimanded.

"Then stop wasting yourself, brother," the annoyed male voice huffed.

Tony's mind froze, then started connecting dots. His bearer coming into powers . . . wasting himself . . . not remarking on a comment about time . . . "Are you the Infinity Stones?" he finally asked, still trying to comprehend what was happening.

All five voices he had heard before buzzed. "A pleasure to finally speak to you at last, Anthony," the bell-like voice said.

Tony was speechless for a few seconds; he had never imagined the Stones would have voices, let alone sound so . . . alive. The five were speaking like they were siblings, yet still held such power in them –

Wait . . . five voices? That couldn't be right. "Shouldn't there be six of you?" were the first words out of his mouth when his tongue was untied.

The eldest voice started laughing while the annoyed voice admitted, "I was not expecting those to be the first words he said after that little reveal."

"You weren't around him for very long, brother," the accented male voice reminded him.

"Sister?" the alto voice called out.

"I'm here." Tony almost jumped; Reality's female voice sounded so young, it was like he was hearing a teenager. "I apologize; after my time as the Aether, it is difficult maintaining a different form."

"It's fine," Tony waved the apology off, then froze. "I just accepted an apology from an Infinity Stone."

The annoyed voice snorted again. "Has he still not realized he is speaking to us?"

"I highly doubt he has ever spoken to any of us in this form before, brother," the accented voice countered.

"The man has constructed Artificial Intelligences far more advanced than the rest of his race has ever imagined and has built his suits from nanites, yet still cannot comprehend us speaking to him?" the retort came.

God, they really did sound like brothers. "I've never heard any of you speak, and none of you have been particularly vocal before, so pardon me," Tony scoffed.

He wasn't expecting the silence he received after that statement. "That is because you never could have heard us speak before," the bell-like voice said. "Entering my world has allowed you to do so."

"Your world?" Tony repeated.

"The Soul World."

Well, that answered the question about which Stone that was. Then the words caught up with him, and he swallowed the sudden lump in his throat. "So," he tried to clear it. "I take it you're the Soul Stone, then."

She hummed in confirmation. "I am."

Tony nodded, absently pacing. A puzzle to figure out the rest of the Stones . . . he was good at puzzles. "Barton said the Red Skull was the guardian of you," he finally said. "And the Stone he had before . . . he had the Tesseract. That other female voice, is that the Space Stone?"

The alto voice chuckled. "Well done."

So that left the two other voices. He knew the eldest was Time, thanks to the ever so helpful hints dropped by his . . . well, he supposed he could call them brothers, based on what Wong had said. These six Stones had been created around the same time. And based on what each of those voices had said . . . "I know that accent," he spoke up. "It's not the same voice, but it's close to what J.A.R.V.I.S. and Vision had. You're the Mind Stone."

"I am indeed," the accented voice said warmly.

Tony nodded decisively. "That leaves Mr. Pessimist as the Power Stone, I suppose."

Space laughed as Power growled. "Careful, Stark. But yes, you are correct."

"Good," Tony nodded, absently rubbing his hands together. "OK, that's out of the way. Can I ask another question? Kind of important, I'll let the rest of you talk after I get an answer."

"What do you wish to know?" Power asked.

Tony took a deep breath. "Pep said they were gonna be OK. Was she . . . right? I barely remember anything except for what she said."

"Virginia was correct," Space informed him. "Thanos and his armies have been destroyed. They turned to dust, just as half of every population in the universe was."

"Every population has been saved," Reality chimed in. "You saved them."

Tony sighed in relief, feeling himself relax. His snap had done exactly what he had hoped, then. Thanos would no longer be a threat. "Good."

"It is," Time agreed. "But we are not satisfied."

And there went that relaxed feeling, Tony thought as he stiffened again. "I'm sorry?" he asked.

Power was growling again, except Tony had the feeling his anger was not aimed at him. "Thanos was never supposed to gain us," he spat. "He never should have been able to."

"He never should have even touched us," Mind agreed, sounding as annoyed as his brother had been moments ago.

"My Keeper did all in his power to find a way the Mad Titan would not win," Time said gravely; with each Stone's voice, Tony felt the air thicken with their fury. "He found one among over fourteen million."

"He never should have had to look at all," Space hissed.

"We never should have been used for genocide!" Reality cried. "All the chaos! All the death! That is not our way!"

"Peace, brothers and sisters," Soul soothed. "We have a chance to right this wrong."

Tony swallowed, feeling the fury ooze away. "Guessing that chance involves me."

"Indeed."

Flickers of smoky red energy flew past Tony's eyes, and six images formed in front of him: the orange Soul Stone, glowing ominously; the tendrils of the Aether twisting and turning; Strange's necklace, the Stone inside pulsing green; Loki's scepter, the jewel at the tip glittering; the Tesseract, energy wisping about inside; and a stone-like orb, appearing to vibrate, ready to break at any moment. "When we were created, we scattered ourselves across the universe, hoping that a being such as Thanos would never find us," Time explained.

"Except he did," Tony felt the need to point out.

Space made a sound similar to the clicking of a tongue. "Because not all of us found our correct Keepers before he found us."

Tony paused. "Your correct whats?"

"Our Keepers," Power repeated. "We have never bowed, never submitted, not until Thanos forced us into his gauntlet and used us as he wished. Prior to then, we only aided when we wished. We were never truly controlled, and we never would have been."

"The only ones we would truly allow to control us of our own free will would be our Keepers," Soul continued as Tony looked at the images in front of him in a new light. "Guardians who could use us correctly and properly, allowing us to reach our full potential. We separated ourselves in hope that our Keepers would find us and that the wrong person would never unite the six of us." She sighed in disappointment. "And yet, Thanos did exactly that."

"And when he snapped his fingers, he killed half of every population in the universe," Tony murmured.

"And you and your fellow Avengers found a way to reverse that action," Mind said. "Yet still, after Thanos snapped his fingers a second time, we died and could no longer be used."

Reality made an upset sound that sounded remarkably similar to a whine from Tony's daughter that he almost wanted to find a corporeal version of her to hug comfortingly. "That would be our legacy. One of death and destruction and genocide. How could that be?"

"It will not be," Soul promised. "This can be fixed, sister."

"You're incredibly optimistic," Tony frowned, twisting and turning. It was still a bit weird to hear these voices all around him and not see any source at all. At least with his A.I.s, he knew they were coming from a speaker somewhere. Here in the open air? That was just weird. "How does this get fixed?"

"Find our Keepers," Soul answered simply.

Tony blinked once, then twice, then shook his head. "Uh, two small problems there. One: I'm dead. Two: so are the six of you . . . at least the versions Thanos used, and the ones I used need to go back to their timelines."

"Yes, you – and we – are dead," Soul acquiesced. "But you are also correct . . . we are the versions that you used."

"And we are certainly not dead right now," Time said. "We still have our power. And we can use that power to send you back."

Tony took a physical step back, he was so surprised. "Send – " He almost choked on his words. "Send me back?!"

"Back to a time where you could find all of us without Thanos gathering us," Power confirmed.

"To a time where our Keepers could be saved and shown their rightful paths," Mind continued.

"A time where we can be bonded to our true Keepers once and for all," Space finished.

"And we want your help in doing so, Anthony," Soul said softly. "Only the son of Laufey knew of this threat better than you."

Tony bit his tongue, having to stop himself from saying anything against Loki, the one who had brought the Chitauri to Earth and started his nightmares in the first place. According to Thor, Loki had aided him when he needed him most, and he had given up the Tesseract to save his life. Thanos had killed him when Loki had tried to kill him to save Thor. At least he had died better than who he had been. "I don't suppose you can actually tell me who these Keepers are?" he asked.

Reality laughed, and God, Tony was really imagining that as an older Morgan's laughter. "You know who they are. You have met them all before."

"Because that really narrows the list down."

"You will find them, Anthony," Mind said. "You did in the end."

Tony sighed, pinching the bridge of his nose. These Stones were really making their case to him. "I can change things?" he asked, hearing his voice crack. "Everyone who died, all those bullshit decisions everyone was making . . . "

"They can be changed," Reality confirmed. "How much can be changed, however . . . not everything can be. Some events must happen for destiny to arrive."

"And this timeline?" Tony asked. "With Thanos, the Decimation, my death, yours?"

"Will cease to exist once you are sent back," Time answered.

Tony scratched the back of his head; now he was really almost convinced. "Sounds like a lot for just little old me," he said.

It was Mind who laughed this time. "We never intended to send you back alone."

Tony's head shot up at that, and it was Soul who spoke this time, a tinge of sadness in her voice. "Never before has anyone fought to be the sacrifice to gain me. Never has anyone been so ready and willing to die to gain me. She deserves the same chance you have now."

Tony's heart skipped a beat or five at Soul's words, but there was a bright flare of orange light before he could speak a word. He flung an arm over his eyes, closing them to avoid being blinded, but just as quickly as the light appeared, it was quickly gone. All that signified something had happened was a sharp inhale of breath, then a shaky gasp of "Tony?"

Tony quickly lowered his arm, and his astonished brown eyes met shocked, teary eyes of emerald green. He swallowed around tears of his own as he took in the braided red hair, still with a hint of blonde in it, rain jacket and dark clothes his friend was wearing before his face split with the widest grin he had felt in a while. "Nat," he choked out. "Did you miss me?"

"Tony!" Natasha Romanoff burst towards him when he spoke, and Tony finally let his own tears fall as he hugged his teammate, burying his face in her hair as she clung to him. "Oh, my God!"

"I'm so sorry, Nat," he breathed. "What happened to you – "

"Did we win?" she interrupted, pulling back to look up at him. "Did we get them all? Did we win?"

Tony gulped. "Yeah," he nodded jerkily. "We won. We got everyone back. Thanos is gone, too."

Natasha blinked. "But Thor – "

"Killed him, I know," Tony nodded. "It's a long story. Basically, we had to fight him and all his armies again."

Natasha appeared to mull that over before horror dawned in her eyes. "Then why are you here?" she asked.

Tony took a deep breath. "Because I had to use the Stones to end him," he answered. "I used the ones we gathered to decimate Thanos and his armies, just like he did to our friends and everyone he killed in the universe. I didn't survive that."

Natasha put a hand over her mouth, eyes wide in shock. "Tony!"

"Nat," Tony put his hands on her shoulders, looking right into her eyes. "We can change that. We have a chance to make sure that never happens."

Natasha's mouth opened and closed repeatedly. "What?" she finally sputtered.

"Anthony speaks truly, Natalia Romanoff," Time's voice rang out, and Tony had the rare pleasure of seeing Natasha jump and flail about, trying to find where the voice came from. "You have a chance to set things right."

"Where – ?" Natasha began.

"It's a long story, but it's the Infinity Stones," Tony winced.

"The what?"

"Yeah, they sound like typical siblings."

"We're not typical," Power grumbled.

"On that, we agree," Mind snorted.

"See?" Tony waved a hand in exasperation. "But Nat, they can send us back in time to get the Stones before Thanos can."

Natasha's jaw dropped. "Every mistake we made, every person who died?"

"We can do what we can to fix them," Tony nodded eagerly.

Natasha swallowed hard, a disbelieving smile forming on her face. "Oh, my God . . . "

"And we just need to make sure the right Stones end up with the right people," Tony nodded.

Natasha blinked. "What?"

"Thanos was never supposed to have us," Time explained patiently. "We were meant to be with our Keepers, our true guardians and protectors."

"Oh," Natasha said faintly. "So . . . Thanos – ?"

"Is certainly not any of our Keepers," Power said dryly.

"Do you know who they are?" Natasha looked at Tony hopefully.

"I can think of one," Tony admitted, eyeing Strange's necklace; the green light seemed to be winking at him. "But the rest of them? No clue."

"You have met them," Space promised. "And you will find them again."

"They get cryptic like this," Tony gestured towards the sky. "It's very annoying."

"Careful, Stark," Power growled.

"Make your decision," Soul interrupted. "Remain deceased and remain in my world, or receive the chance to change time, change what happened to you, and set things right."

"Choose!" Reality called.

Natasha seemed to stare into space. "Nat?" Tony asked quietly.

"If we do this," she said quietly, "you'll be risking what you had with Pepper. What about Morgan?"

Tony's heart twisted at the thought of his wife and daughter. Honestly, that was the biggest con he could think of. Did he want to have a timeline where he may not have Pepper? Where Morgan may not exist?

But other thoughts crept into his head as well. What lives could have been spared when Vanko was a problem? How many could have been saved in New York if the right action had been taken earlier? How could the Mandarin and Extremis have gone? The fall of S.H.I.E.L.D., Ultron, the Sokovia Accords . . . the deaths of Pietro Maximoff, Loki, Quill's girlfriend, Vision, Natasha, and everyone who were decimated?

He swallowed hard. "I had five years with Pep and just a little less with Morgan," he said softly. "I wouldn't have had that if it weren't for Strange's decision to give up the Time Stone. But he never should have had to do what he did. If we can even do a fraction of what we may be able to . . . this is worth it, Nat."

Natasha looked up at him, licking her lips. "Really?"

"Yeah," Tony nodded. "But if we do this, Nat . . . I don't think I can do this alone. I need your help, teams or loyalties be damned. Please, Nat."

Natasha stared long and hard at him before she shakily nodded. "Together," she decided.

Tony felt his shoulders slump in relief, and he nodded as well. "Together," he agreed. She silently held out her hand, and Tony squeezed it tightly. "We're ready!" he called.

"Excellent."

The world around them seemed to hum, and the images winked out of existence. "We have made a decision," Time declared as Tony reached for Natasha's other hand, which the Russian took without hesitation. "A time that allows the two of you to think individually before coming together once more at the most crucial point. Your destination is the year 2008, fifteen years prior to your last year."

Tony's eyes widened, and Natasha looked up at him in shock. "The Ten Rings," she breathed. "Your first year!"

Tony nodded numbly. "Stand strong," Mind said. "You'll find there is much you will be able to do once you set your minds to it."

"But be wary," Power warned. "Thanos will still seek us. Should he even collect one of us, it will be an even harder fight for you to win. Thor told you what he was capable of with just me. Take care."

"Well," Tony took a deep breath, looking at Natasha. "See you soon . . . Natalie."

Natasha smiled. "See you then, Mr. Stark."

Tony grinned. "Good fortune, Anthony Stark and Natalia Romanoff!" Soul called as tendrils of green, orange, red, blue, purple, and yellow spun around them. "Good fortune in your challenges to come!"

Then the colors obscured Tony's vision, and as the Soul World faded around them, he closed his eyes, mentally preparing himself to wake up wherever in his timeline the Stones dropped him. The last thing he comprehended was Natasha's hands squeezing his, and him barely managing to squeeze back, and then he felt he was freefalling.

Here we go again.

A/N: So there you have it, the idea of the fic: in this version, each Infinity Stone has a Keeper meant to guard it with the abilities and the will to use it. It's basically like Mjolnir, except with one person - only one person is worthy to guard and use each Infinity Stone, and hint: Thanos isn't the correct Keeper for any of them. Feel free to guess who some of them are!

This will be a rewrite of the Marvel Cinematic Universe from Iron Man onwards with the exception of "The Incredible Hulk" - I haven't seen it, and Tony's only appearance was at the end of it, so unfortunately, it gets booted out. But every movie following that including Tony and/or Nat (or maybe not!) is fair game.

I will also say that there will be different pairings than in canon. This book is about making changes to canon for a better endgame, and I have nothing against most of the pairings (though I wasn't a fan of Nat/Bruce), so I'm changing some up. Hopefully everyone likes what I will choose!

Anyway, I hope I did a good job with Tony's POV and kept him in character, as well as provided a good representation of the Stones. If you didn't get each of them: male, baritone, mostly annoyed/growly is Power; young male, accented is Mind; eldest male is Time; sultry alto female is Space; young female Tony compares to Morgan is Reality; and female, bell-like is Soul. I see the six of them as siblings since they were created around the same time, so I tried to incorporate that into them.

Next time I update, whenever that will be, we'll be delving into the movie that started it all - Iron Man!