A/N: I'm sure that the Avengers will have to handle some pretty crazy stuff over time, and this my take at what they could possibly have to face (with Tony in the main role). The story was originally planned as a One-Shot, but then it just got way too long for one chapter. At the moment I'm aiming for three chapters, with two more to go.

Disclaimer: all the characters belong to Marvel

Forwards

Whatever kind of stupid joke this was supposed to be, Tony didn't like it. Not one bit.

One minute he'd been standing in the lab, finishing the last touches on the new arc reactor model, and in the next there had been a weird cracking sound followed by an awful bright light before the lights went out completely – what shouldn't have been possible to happen, really, because the tower still had more than nine months of energy left. That meant that (if someone hadn't managed the nearly impossible feat of actually destroying the arc reactor in the Upper New York Bay) this was a prank. A really lousy one, because everyone and their mother knew that you didn't mess with Tony Stark if you knew what was good for you.

He blinked to adjust his eyes to the almost total darkness of the room.

"Jarvis?" as Tony had predicted there was no answer. Someone was going to pay for this.

Sighing he ran a hand through his hair and turned into the direction of the door, the faint blue glow coming from his chest giving off at least enough light to prevent him from crashing into any unfinished projects lying on the floor – though the concrete looked awfully clean and that engine over there certainly hadn't-

"It's him. Definitely." the voice was barely loud enough to hear, even in the total silence of the room. It seemed to come from nowhere in particular, meaning that someone was using the speakers from outside, meaning that that person was talking to someone in the room that wasn't him. Tony stopped dead in his tracks.

"I'm starting to get pissed." his voice was light and cheerful, "And you don't want to see me pissed off."

There was someone in his house and they weren't invited. One part of Tony's brain tried to figure out how they had gotten inside the tower without anyone noticing, had come up to his private levels without neither him nor Jarvis noticing and had managed to cut off the power and catch him by surprise in his own damn home, while the other calculated if calling the Mark VII down three floors would damage the statics of the tower enough to have the upper levels collapse.

"Jarvis, lights on. Slowly." the voice came from somewhere on his right and Tony's head instantly whipped around to glare at the intruder.

What really surprised him however was the fact that the lights indeed were turned back on immediately – which meant that the tower was still plugged in after all, what inevitably lead him to the question why the fuck his AI was doing someone else's bidding.

"…and who are you?" the "and what the hell are you doing in my tower?" was quietly overlooked since the first would lead Tony to the second anyway. Not to mention that at the moment it was quite hard to sound indifferent rather than letting the boiling rage at being played like that show in this face or voice.

A crooked grin appeared on the young man's lips, "If you are really Tony Stark, you know."

And now the fucker was being cryptic. Just perfect.

Raising an eyebrow the billionaire took a step closer towards the other man, who didn't look the least bit intimidated at seeing Tony advance. In fact he looked a little forlorn standing there in the vast, almost empty laboratory – like a kid that got lost completely and didn't know what to do.

Their eyes locked for a second, brown boring into brown. The younger man's eyes were empty of any emotion, no hate, no anger, no hurt. (So this wasn't about some kind of revenge after all.) He wore a pair of shabby old jeans and a bland black t-shirt. His hair was brown and the longest strands tied back into a small ponytail …all in all Tony didn't find anything remarkable about the man. Even his height was pretty much standard though he was just a tad on the short side, probably something in the middle of him and his-

Tony's brain was absorbing thousands of things at the same time: the slight difference in height, the frame that was only a little bit leaner, the form of the eyes, the straight nose and the higher cheekbones… the many differences and just as many similarities.

"Jarvis." there was an edge to his voice that shouldn't have been there.

"Yes, sir." his AI actually answered this time around, and Tony couldn't really say if that was a good or a bad sign.

He cleared his throat, "…what year do me have?"

The silence stretched until it seemed nearly unbearable.

"I'm afraid I'm not entitled to share this information with you, sir."

For a second the billionaire allowed himself to close his eyes. When he opened them again he caught and held the other man's gaze easily. There was pain and longing in those brown eyes …a lost child for sure.

Another five steps and he was holding his hand out to the other.

"Anthony Edward Stark."

A genuine smile crossed his son's lips when they shook hands.

"Jackson Anthony Stark."

After that they just stood there, still holding hands – usually it would've been way too unmanly for Tony Stark to hold hands with another man, but this was his son and the implications that that thought had running through his head made him feel a little dizzy.

"I assume there actually is a reason why I'm here." he fell into his typical nonchalance out of habit.

"Yes." Jackson nodded slowly, "But let's take this upstairs. The others… there are a few more people you need to meet."

Without waiting for an answer his son turned around and Tony followed him out of the room and through the tower towards the top floor. He noted that the place didn't differ much from his memory and silently wondered if no one had had the heart to change anything about the layout of the building or if they'd actually turned it back to its original state for his sake.

They were in the elevator when Jackson started talking again, "The people you're about to meet are all familiar with you …or at least the older version of you. They… we miss you."

The implication wasn't lost on Tony, like the pain in his son's eyes hadn't been.

Theoretically speaking he didn't have any connection to this young man, his fate or his world, but the words still managed to choke him. This was his son, his son in his late twenties that had just told him that we was dead – and it wasn't the not-alive-anymore part that rocked him to the core, but the thought that his kid had lost him probably at the same age he'd lost his own father.

"I… I'm sorry." Tony didn't know where it came from, but he really meant it.

"Don't be, Dad." and again there was this genuine smile on Jackson's lips. The love in his eyes would have made Tony stagger if he hadn't been leaning against the wall of the elevator.

The car came to a stop just seconds later and the elevator opened to the all too familiar side of his large living quarters. The furniture was different, but he had expected that much – what he hadn't expected however was the relative darkness of the vast room. The panorama windows were darkened and obviously blind to the outside.

So he wasn't supposed to see how future Manhattan looked.

Stepping forward to take the room in, he only became aware of the figures sitting on the couch when two of them suddenly came rushing towards him, taking him totally by surprise when they latched onto him.

"Papa!" before Tony knew it he had his arms full of female, two equally dark blond heads pressing against his chest and surprisingly strong arms squeezing him for all he was worth. He didn't really know what to do about the brusque attack, but this were obviously his kids (strange that he'd never imagined having anything more than a son to carry on the Stark name) and so he did what he was supposed to do and hugged them back. It felt strange but left a warm tingling in his chest.

"Anna, Sofia, let go. We just got him back, don't crush him to death." Jackson sounded annoyed but had the telltale glint of unshed tears in the corners of his eyes.

The picture left Tony with a sudden rush of fatherly pride he hadn't been prepared for.

Damn, he'd managed to raise some find kids (or Pepper had because he'd been dead to early, but going along with that line of thought hurt too much so he pushed it aside immediately).

They did as their brother had told them, two identical set of grey eyes looking up at him when the young women let go of him. They were both smiling, a happiness showing on their faces that left him momentarily breathless. God, his girls were beautiful. And they loved him. And-

…and he knew these eyes.

The thoughts were spinning in his head now, leaving him confused and raw and hurt – because he was Tony Stark and his head worked too fast for his own good. He looked them over and he knew it, he drew the conclusion that was inevitable. It spoke of death, of more people killed too early, and it reminded him that they weren't invincible. They were mortal, every single one of them. They would die and-

"Tony. Stay focused." he voice was quiet and controlled and he would've known it everywhere.

His head snapped around and indeed there he was, Bruce Banner sitting on the dark grey couch beside Steve, his eyes gentle and his smile apologetic.

For once words failed Tony Stark and the people around him seemed to recognize it, the twins leading him towards the couch and carefully placing him on a chair. Jackson followed and Bruce and the Captain just watched him, neither saying a word.

They were old (or at least older in Steve's case). Banner's hair was grey, his face had more lines than Tony remembered and his shoulders weren't has tense as they had been in his timeline – but he was still younger than she should've been according to Tony's rough calculation of the years passed. The doctor looked to be in his late fifties or early sixties. Beside him Steve Rogers looked like he could have been Bruce's son, his body not a day older than forty …so this was the price that came with the creation of super soldiers and indestructible forces.

"Get your father a drink, Jack." the words surprised him, coming from Steve of all people.

"But…" his son looked back and forth between them, "Dad doesn't-"

A sharp glance from the Captain made the young man shut up and Tony wondered what it was he didn't in this time. Drink? Drink when his kids were present? Drink in the middle of the day?

He forced himself to focus on the people sitting around him.

"What… this… tell me." his mouth was dry as dust and the feeling sent him back years ago, walking through a desert without direction, weak and thirsty and completely alone. A shiver ran down his spine at the memory and the only thing that stopped that line of thought was the cool glass that Jack pressed into his hand – he downed the content without even checking what kind of alcohol it was.

The liquid burned down his throat and gave him back a certain sense of reality.

"You have to read this first." his son looked almost embarrassed when the handed him a stack of paper. Paper, because data could never be really destroyed. There was no guarantee that at least parts of the original code wouldn't be retrieved. Paper could always be burned.

"You probably won't understand all of it. There's no Lyle Drive in your time and the theory about wormholes is shady at best, but you'll only need the rough function of the principle of time lines, the direction problem and the additions to the space-room continuum." Jack used the terms in the same way he would have, like they were the most natural things to talk about.

So his son was a genius alright – Tony couldn't say that he was overly surprised.

He made a motion to begin reading (cursing that of course his glasses were still in his lab, decades away), but was stopped by a firm grip on his right wrist.

Jackson looked nervous, "You have to promise me something, Dad. Don't try to recreate it …please."

"Why?" the billionaire would've been lying if he'd said that Jack's words hadn't attracted his attention. Whatever this was, it had the promise of being very exciting. Time travel. Why hadn't he thought about it sooner? That was basically what Thor must have done to get from Asgard to earth and back. Damn, why hadn't he ever asked him about it?

A faint laugh from opposite him made Tony look up. It was Bruce.

The doctor shrugged, "I knew that you'd be head over heels into it."

"What did you expect, Bruce?" he gave him his best beaming Tony Stark grin, "Time travel? I mean that's like a completely new section of candy land opened just for me. Whatever the problems are, most of them can possible be avoided with enough power to stabilize it. With an arc reactor-"

Their faces fell all at once and Tony instantly knew that he'd said something wrong.

"I told you this wasn't a good idea. He's still too young." Steve's blue eyes were hard. There was no accusation in his words, at least not directed at him – and that was something new to Tony entirely. The Captain for once didn't think it was his fault.

"You don't have the technology for it yet." those brown eyes were pleading with him, and sadly he wasn't entirely immune to them, "If you'll try it'll go wrong and… please, Dad. We need you. You need to read this, but used in the wrong way it can backfire horribly. I can't let anything happen to you."

It wasn't about what Jackson had said, but about what he hadn't said, and Tony was very well aware of it. There was a "I can't let you die." in there. And another unsaid "Not again." right after it – this was his kid pleading for his life, and suddenly the candy tasted very foul in his mouth. He hated it, hated every part of it down to the fact that his own child had to plead him to not get himself killed.

"No playing with cool future stuff until I'm old enough, I get it." he threw his hands in the air in a theatric fashion and felt everyone around him relax almost instantly. The hand around his wrist vanished.

After looking around to make sure that no one was going to stop him this time around, Tony finally took out the first sheet of paper and read. And read, and read, and read. He didn't know how long all of it took, but it must have been the better part of an hour.

When he was finally done with the last page he put the papers down in front of him, leant back and grinned.

"This", he tipped his fingers to the stack, "is incredible. Fantastic. I'm not even sure I understand the full theory behind it. This has the potential to change our world forever. Transport, weapons… there probably isn't a field where you can't use it."

Tony meant it. This wasn't candy land, it was candy world. The only downside he could find was that he wasn't allowed to play around with it.

"You did that?" he looked at Jack, who actually blushed a little, "That's genius. All of it."

"Actually…" his son avoided his gaze, "You and Uncle Bruce invented it."

Banner started talking before Tony could ask any more questions, "He means that you invented it. All I did was getting you back on track when you threw a tantrum and being there to bounce ideas off of that you hadn't tested at the time."

He raised an eyebrow but then shrugged, "Well it's nice to know that I never stopped being a genius."

All of them laughed at that and it actually settled a little of the tension in the room. The silence was almost comfortable now, at least until someone spoke again.

"We'll talk about a few things now." of course Cap was all business (some things never changed), "Some of them you need to know, some we want you to know and some are perfectly irrelevant."

"And because I don't know the difference it will be really hard for me to figure out what parts of the timeline have to change, what parts can change and what parts can't be changed …thought I doubt you're sure about the last thing either." Tony understood the concept perfectly fine. Safety regulations. They couldn't just tell him what exactly they wanted to change because him trying to prevent it from happening would most likely only make matters worse.

"…I needed almost two weeks to get that." Steve sounded resigned.

Tony couldn't help but chuckle, "Still behind on technology aren't you, Cap?"

Grunting something unintelligible the blond fished a piece of equipment out of his pocket that suspiciously looked like an iPhone, ignoring the dirty looks he got from Jack and the twins.

"I guess that's a yes then." the grins on the others faces told the billionaire that he was indeed right with his assumption. The Captain just pouted at being busted – what kind of looked hilarious on a 40 year old guy that was all muscle.

"What happened to them?" Tony would have liked to banter some more, but he just had to know. They were his friends (family, even if he would've never admitted that out loud) and it was obvious that they weren't there anymore.

No one seemed really willing to answer the question and he hated himself for digging up what had to be painful memories.

"Natasha? Clint? Thor?" he listed them one after another, and then, after a pause were his heart started beating ridiculously fast because deep down he was aware (but refused to believe) what her absence meant, "…Pepper?"

The silence stretched too long.

"Our father…" Sofia started but faltered, grasping her twins hand tightly before she continued, "We never met him. He died before we were born. He saved mama on a mission in Shanghai and went back in to finish the job… but he never came back."

It didn't surprise Tony. Not in the least.

She grabbed his hand now and he let her. They had had called him papa before and the understood – he desperately wished he wouldn't but he did. Decades later the five people in this room were all that he had left of the friends he had just seen being happy and alive hours earlier.

"We were six when mama died." a shiver ran through the young woman's body, "She couldn't go on alone. She got careless."

Another thing that didn't surprise him.

Pulling her closer let the girl (his daughter, blood didn't matter) lay her head on his shoulder. Her sister was more composed but the look she gave him was even harder to stomach, because Natasha had looked at him the same way too many times to not remember it.

"What about Thor?" Tony was desperate for someone not having died.

The grin on Jack's face was the best news he'd had in the last hour, "King of Asgard. He can't come down as here often as he'd like to do, but Tristan stops by fairly often to visit his Mom. Jane Foster, the woman he never shut up about? …yep, they have a child. She's still living here, but there was talk about moving to Asgard when her life on earth was over. But don't ask me how Thor is going to pull that one off."

That was a surprise, though it really shouldn't have been.

"Let me guess: Tristan is big, blond and too stubborn for his own good, pun intended." he could imagine the kid without ever having seen him, and that said something.

Anna actually rolled her eyes, "You wouldn't know. Tristan, wielder of the storm sword Miekka, half-god and biggest loudmouth of the seven worlds… he never shuts up about it, ever."

Soft laughter filled room. It was good to know that some of them actually had a more or less happy future ahead of them. It didn't make the deaths less painful, but it gave Tony the hope that if he'd do it right maybe it could be like this for all of them …when had he became such a helpless romantic anyway?

It became quiet once again and he was painstakingly aware that there was only one person missing that they hadn't talked about yet. Brown eyes met brown eyes once more and Tony Stark knew that he really didn't want to know what his son was about to tell him …he could listen to the deaths of Clint and Natasha, not because he didn't care for them, but because possible death had always been part of their job. Pepper… she'd never had anything do with this stuff. He'd kept her out of all of this as good as possible because he knew that he couldn't watch anything happening to her. But it had – and he hadn't been able to protect her.

"Mom…" Jack began, slowly, with love in his words and tears in his eyes, "Mom was-"

He was interrupted by the sound of steps coming from the stairs and the angry grumbling of a girl that came along with it, "Jackson Anthony Stark, you lousy…"

The room froze and Jack broke eye contact, exchanging a terrified gaze first with the twins and then with Steve. Bruce was the only that looked utterly calm, something akin to approval showing in his eyes when he and the billionaire locked eyes for a second.

"Jack! You should know that overriding my access codes to the upper level is a stupid joke, especially when I-"

The girl stopped dead in her tracks and Tony stared.

She was only a teenager, a good three inches shorter than he was used to, and her eyes were brown instead of blue, but she had the same face and the same reddish blond hair. She… his daughter looked like a miniature of her mother, furrowed brows, puckered lips and all. (The face he thought he'd never see in this reality.)

For a moment nothing happened, but then the frown left her face and her eyes became wide.

"Daddy!" she dropped her bag and ran and he was up before he realized it, taking the last step that was needed to hug the child as tight as he could, slender arms returning the gesture immediately.

"Daddy, you're back! You're back." she held onto him as if her life depended on it, sobbing against his chest and staining his shirt with hot tears.

Tony Stark did do many things in public. Crying had never been one of them. He was a Stark, he never cried. Crying was for the weak, the people that became desperate because they didn't find way out. He had no reason to cry, he always found a way out.

So when held his daughter and felt the tears running down his cheeks he swore to himself that there would be a way out. He'd find one. This wouldn't happen again, not in his timeline. No matter the cost, he would make things right, for his children (all four of them).

I am neither an expert in physics nor in the theory of time travel, so forgive me if I made same grave mistakes.

TBC.

Any kind of feedback is very much appreciated.