Warning: Major spoilers for Infinity War
This is all of the thoughts running through Tony's head as he saw the consequences of their failure.
Ashes
They had failed. Strange had, for some inexplicable and unknown reason, given up the very Time Stone that he'd sworn on his life to protect, in exchange for the life of an undeserving and egotistical man he'd just met. It wasn't a long wait after that until the failure of the defenses back on Earth became abundantly clear.
The big blue guy dissolved, and Tony watched with bated breath as he slipped away to nothingness. He was unable to help as the wizard went next, slipping away but not before uttering a few words.
"It was the only way."
The only way for what? For them to die? None of this was making sense, except for the fact that half of them would be toast. This was too much to think about right now. Maybe the warlock had had a plan, but he was gone now and Tony's mind was reeling far too much to overanalyze the man's last words. Instead he turned back to the group, noticing their numbers were beginning to dwindle.
He exchanged a quick glance with the guy: Star-fruit or whatever his name was. The man looked down, noticing himself beginning to fizzle away as well. At first he was alarmed, but then he met Tony's stare with a look of resignation. It pulled at his heartstrings, even though he barely knew the spaceman. All of his friends had died, including the Gamora girl whom Tony had deduced to be his lover. He silently thanked that Pepper was down on Earth.
Shit. Pepper. Was she alright? He had no way of knowing if she was vanishing like the rest, probably confused and scared. He would have to call her as soon as he was able to fix the communications on his suit.
These emotion-filled thoughts ran through his head as more logistics also filtered through. There were seven of them a mere minute ago. Now there were only three. If his calculations were correct, and they usually were, then they were done disappearing.
His mind couldn't decipher between two starkly-contrasting emotions: panic and numbness. He knew half his friends were likely gone, maybe even his wife. That kind of loss takes a while to set in, and he simply felt detached.
On the other hand, this wasn't ordinary loss; they had lost the universe. His heart was racing as he didn't know what to do next. The wizard, the only one he knew to be even a little bit capable at finding a way out of this, was gone. Him and the kid were stranded here, having crashed the ship they'd arrived on. He had no idea who was still left back on Earth, or if Thanos had decided to screw it and decimated them all to get the stone. The thought caused his stomach to do a flip, and made him nauseous. He managed to push it aside - he couldn't afford to be thinking like that.
Giving himself a quick mental check, he wondered if he himself would vanish. It was unclear what the process felt like, or how you knew it was happening, but a quick look down confirmed for the moment at least, that he was intact.
His rapidly-beating heart suddenly stopped, and might've even broken the moment he saw Peter stumble. "Kid?" he asked, his brow furrowing. That wasn't good. This was not good. He couldn't lose the kid. He just couldn't.
Maybe he was fine. It was shocking, to lose half the universe to a genocidal titan and see friends vanish into thin air, ceasing to exist. The thought was making Tony's stomach churn himself, feeling the need to sit down. It must have been multiplied being witnessed through the eyes of an innocent teen. He was probably just traumatized, the weight of what had happened sinking in. Tony had felt panic attacks before, and maybe the younger hero was experiencing one right now.
"I don't feel so good." Peter was looking up at him scaredly, panic clearly written across his face.
It was all Tony could do to keep the fear out of his own expression as he knew what was happening. He couldn't kid himself; this wasn't a mere panic attack. He had to stay strong, though. The kid - his kid - was scared and he needed to be there.
This transition seemed to be going slower than the others, but maybe it was just his mind. The others, they had been upsetting, but they were more like colleagues than friends. Not Peter. The first things to change were his eyes. The usually vibrant and youthful chocolate color was clouded over, replaced by the tell-tale dull brown.
"I don't know what's happening…" Peter's tone was thick with urgency now, as he began to feel what it was like to stop existing. Tony felt like a helpless bystander, as this was one problem he did not yet know how to fix. Rather, if he could fix it.
"Mr. Stark-"
It was the beginning of a plea, Tony knew as his heart clenched, to stop the inevitable from happening. There was no time for it to be finished, as he fell forward. He was caught, and just held tightly. Tony Stark wasn't a hugger, unless it came to Pepper and even then only when necessary. But he held the kid close, wishing he could keep him there forever. One hand holding him up, the other went to the boy's hair. He ran his hand through it, in what he hoped was a comforting gesture. Sentiment filled him, as he realized it was likely the last time he would get to ruffle it.
"I- I don't want to go." Peter was begging, gripping Tony's arm as if it were his lifeline. "Please, please, Mr. Stark. I don't want to go!"
He couldn't think of anything to say. Comforting people was never his forte, but he certainly wished he had that skill now. He wanted to say something, anything, to ease the boy's pain. All he could manage was an "I know, kid," around the lump in his throat. He pulled the boy even closer, pressing his head into his chest.
"Please," it was fainter now, not as strong but still holding the same urgency.
Vehemence took hold of his senses. He would be able to fix this - he had to be. There was no way he was letting this kid die, certainly not on his watch.
The tears welled in Tony's eyes as he felt the weight in his arms start to grow lighter. Sure enough, his body was flaking away and being replaced by little flecks of dust. As his hands and legs faded, the fleeting particles swirled in the wind.
As the disintegration progressed, he laid the kid on the rocky ground.
Peter was holding eye contact with him, even through the dusty haze impairing his vision. "I'm sorry, Tony."
He didn't know what the kid was apologizing for. So he didn't answer, not sure what to say. He wanted to reassure him that there was nothing to be sorry for, to tell him that there was a way to bring him back home. But Tony didn't know. This was unlike anything he'd ever dealt with before, and despite all of his brilliant inventions, he was only a broken man. In all of the scenarios running through his mind, he couldn't find a single one where he could bring everyone back. The kid was vanishing before him, essentially dying. He wasn't going to fill his last moments with lies and false hope.
"I'm so sorry."
The dust crawled higher on the boy, as his legs and arms were now gone. It didn't continue to travel upwards. Once it got that far, it began to swallow him whole. Before he could blink, Peter was gone.
It had seemed like his disappearing act had gone on forever, seconds turning to hours. Now, as only some scattered piles of dust sat where his body once lay, he realized that it had gone all too quickly.
The unfairness of it all began to sink in. He wasn't even supposed to be here. That hardly mattered now, and truthfully Tony would've done the exact same thing at his age. But without him, they wouldn't have had that brilliant plan to free Strange from Squidward's torture. He had been a valuable asset throughout the fight, keeping up surprisingly well.
Peter was so much more than just a superpower, however. He'd always wanted a son, maybe to be able to father someone in the way his own dad never could. He'd found that in Peter.
How did Thanos decide who lived and who died? If he really wanted best for the universe, why did he use a system in which screw-up, alcoholic, egotistical Tony Stark got to live over youthful, loving, and heroic Peter Parker?
Had the titan really wanted to ease suffering and pain, why kill everyone he loved? The plan seemed to only cause death and destruction, hurt and heartache.
The arenaceous ashes remaining on the ground were lifted by a gentle breeze, before they too disintegrated. He must have been there for hours, staring at the place where his kid had just been and thinking over all of the different ways he could have prevented this. Peter had been apologizing, but it was Tony who should be sorry. He'd drug the poor kid into all of this, and now he was gone. Every bad thing that had happened to Peter post-Accords was his own fault.
It was with a selfish desire masked behind an altruistic one that he desperately wanted to trade places with one of the ones disappearing. He didn't want to be stuck here to mourn, and grieve, and wonder what to do next.
A hand was on his shoulder, startling him from his reverie but he didn't bother looking up. There was only one other person left on this crummy planet as far as he knew.
A female voice, the one he knew to be robo-girl, spoke softly: "Hey, we should go."
He finally turned to her, wishing she would just leave him be but also acknowledging that she was his only ride out of here. "Alright," his voice was raspy, laced thick with emotion. He found himself unable to stand, and not just because of the healing stab wound still paining him.
"It's not your fault." The woman reassured him, with a gentle smile but one just as broken as his. "The boy would have died just the same were he back on Earth."
It did little to soothe the guiltiness he felt, but gave him the courage to stand. Her sentiment did succeed in reminding him that he wasn't alone - not yet, anyways. "Tony," he offered. If they were the only ones left on the stupid planet, she might as well know his name.
"Nebula," she offered back.
Were he in his right mind, he would have joked about how that's exactly the kind of name he expected a robot-alien-lady to have. His usual sense of humor abandoned him as he glanced back at the spot where it happened. So instead, he nodded grimly and followed behind her.
I know this scene has been written to death, but I thought that I might have a go at it. I'd love to hear your feedback in the form of reviews! I'm also going to start writing some more one-shots, so suggestions are greatly appreciated.