Heaviness is a feeling that Tony Stark is used to.

The weight of Howard's expectations had been heavy. Every goddamn piece of metal he's ever had to pick up as a child in the lab had been heavy. The arc reactor, the iron man armor, the weight of thousands of misdeeds on his back had been heavy.

This is it, Tony thinks, his eyes and nose and mouth and lungs full of nothing but burning, burning ash. This is the price of every mistake I've made.

Peter is (was, a bitter voice singsongs. He was.) seventeen years old. He was an unfulfilled life of endless potential. He was Tony's responsibility. Peter was everything Tony wished he could've been at his age- brave and kind and smart and good- and now he was dust in Tony's hands.

For the first time in his entire miserable life, Tony Stark cannot think.

He's used to thinking in the worst of times, used to his mind running a hundred thousand miles a minute; but in this moment, with Peter's apology still lingering in his ears and the crushing weight of his sins upon his shoulders, Anthony Edward Stark finds his mind blank but for the complete and utter hollowness that he knows comes just before the crash.

Even back in that damn cave, with Yinsen dying in his arms, Tony had been thinking. Even with Stane's betrayal and his arc reactor poisoning him and Pepper free-falling and Rhodey crashing and Ultron and the Winter Soldier and everything, everything- Tony had at least had one single, clear thought in his mind all the while; Fix it.

Right now, he is at a complete loss.

And the crash is coming.

Tony can feel it like bile rising in his throat. He can feel it looming over his mind like a shadow.

Mr. Stark, the boy had whimpered, terror rising in his eyes in a way that made Tony's gut churn. Mr. Stark, I don't feel so good.

There are a lot of things that Tony Stark is never going to forget. All the years of knowledge he's gained throughout his life. The way Howard Stark's breath smelled heavy of alcohol as he snarled at his son. The feeling of his lungs being crushed beneath the weight of a puttering car battery, working desperately not to collapse. The sting of Steve, looking right into his eyes steady and firm and choosing Bucky. The sight he saw flying through the portal with a nuke on his back, the painfully little that the sacrifice of his life would have meant when hardly a portal away there stood an army none of the would ever stand a chance against.

The desperation and fear in Peter Parker's eyes and voice is a new but no less terrifying addition.

Every second that passes adds a soul-crushing weight to his shoulders. Tony sinks.

Please.

There was a seventeen year old boy in Tony's arms, begging to live- and Tony Stark had been absolutely powerless.

Please, Mr. Stark.

Peter clung to Tony like somehow the man could stop all this from happening. Like somehow, the man that is Tony Stark could keep him anchored to the land of the living, like he could fix this.

I don't want to go. Please.

Peter is a child.

Peter is a child and Tony has failed him as he's failed everything time and time again, he's failed. He's failed Peter like he's failed Howard and Steve and Bruce and Pepper and countless innocent souls, he's failed- and none of it matters in the face of a dying child.

I'm sorry.

What Peter could be sorry for, Tony hasn't the slightest idea. But those are not words Peter should be saying. Those are Tony's words.

Tony knows that he has wronged. Tony knows that he has sinned. Tony Stark knows, better than anyone, that he has an unfathomable number of failures and wrongdoings on his conscience that he will never be able to atone for.

This is what all of his errors are amounting to. This is the price of each and every miserable blunder.

But surely, surely this is far too high a price.

Peter Parker is everything Tony Stark wishes he had been- Peter was brave and kind and smart and… good. He was a good man in a way Tony Stark could never be, and he was far too young to be crumbling to dust on some alien planet with his eyes full of fear and pain because Tony couldn't protect him.

Now this.

This, to a man who hasn't had a moment where his entire being wasn't being dragged down, down, downwards.

This is too heavy.