He knocks, and both wants and doesn't want her to open the door. Of course she does, with the chain still on. Her eyes cast around him to find her nephew and instead see just him, and the last piece of her hope falls to the floor and disappears faster than Peter had. His heart leaps into his throat as she slams the door and rattles the chain loose.

She throws herself into his arms, and the way her whole body is trembling is enough to break Iron Man's heart into tiny little fragments. "Oh, God, Mr. Stark, please just tell me he's all right."

Tony holds her as best he can and opens his mouth to say something. Then closes his mouth. There's nothing he can say to make this right, and every line he's tortured himself with over the past forty-eight hours tastes sour in the back of his throat. "Let's go inside." He finally manages to suggest, gently herding her to the couch and helping her sit down. She knows. He can see that she knows, but it still takes three little words for her to shatter. "I'm so sorry."

That's enough. She sobs once and buries her face in her knees, shaking her head and saying, "No, no, no…" over and over again, until the words fade into one long pained sound, a primal noise of despair and grief. Tony clenches his fists and tries not to cry, too. For two days now his throat has felt like cracked sandpaper, and the bags under his eyes are definitely incurring overage fees. The kid had fought so hard…

That's right, he was just a kid. What was he, fifteen? Sixteen? Tony bit his lip and closed his eyes, arms shaking with the effort he needed to stop himself from screaming and howling and screaming some more. Fifteen or sixteen was nothing, it was supposed to be the "first date and stupid mistakes" age, not the "fight for your life, sort-of win, but die anyway" age.

They stay like this for a while, neither able to find their voice, before Aunt May looks up from her knees and says, "How?"

Tony loosens his clenched fists with some effort and his fingers tingle as blood rushes back into them. He owes her this much. "At the end. When everyone else—" he can't say it. Disintegrated. Gone like they were never even born. And sure, half of them were still alive, but absolutely everyone lost a loved one or three. Even the streets of New York City were silent, the few people out drifting to their destinations in a stunned haze. Drivers ignored green lights, lost in thought and misery, and no one even honked to get them moving. The scene would be surreal if Tony could bring himself to notice.

Aunt May straightens herself in her seat and stares over Tony's shoulder, toward Peter's open bedroom door. She's realizing he'll never slam that door again, never call, "Oops, my bad!" or laugh at one of her stupid rom-coms she always made him watch or beg her to make him some coffee too because finals are coming up and who needs sleep anyway? And even though her wailing and tears didn't do it, this expression of hers breaks something in Tony. And he overflows, dam bursting open at last as he babbles, "It's my fault, it's my fault, he was a stowaway but he was my responsibility and I failed you and I failed him, but God, he saved my life half a dozen times and it was his plan that almost defeated Thanos, and we almost won but then he was in my arms and he just," stop talking, now, Tony, his brain says, but his soul ignores it and keeps going, "just drifted away and I couldn't catch him and oh God I am sorry and it's not enough and I," oh there they are, tears, or is it acid coming out of his eyes? might be for how it stings, "I tried…"

That's it. He can't manage any more. He's ugly sobbing now, snot and tears mixing on his face, and he can't stop it and can't do anything about FRIDAY's warning in the corner of his glasses telling him an anxiety attack is imminent and he needs to get his heart rate down ASAP. He wraps his arms around himself and tries to breathe through it but it's no use, his field of vision is rapidly closing in and he can't get any air. He almost wants to laugh at how stupid he's being; he came here to try to offer some closure and comfort to Peter's aunt and instead he's having a breakdown on her fluffy floral print armchair and she must hate him—

And then he's being hugged, so gently that he could be made of wet sand and wouldn't crumble, and to hell with his million-dollar glasses, he buries his face in Aunt May's shoulder. And then he's crying and she's crying and they're both a mess, her shirt is probably ruined and his hair is wet, and they couldn't care less about these things. "I built him the suit." He manages to gasp into her shoulder, shaking his head and trying to pull away. Her grip tightens then, and he stops fighting it after a futile moment. "You should hate me." He mumbles, half-hoping she doesn't hear.

Of course she does, and pulls herself away to level him with the most impressive tear-stained glare he's ever seen. "Tony," She says, thumping him on the shoulder once, "You stop that at once."

Tony blinks.

"Peter chose to go out there with you. He was never happier than when he came clean to me about his internship and he wouldn't have wanted you to blame yourself. We've lost a lot of good people, and Peter was one of them, but it's not your fault. Repeat it."

"It's not my fault."

She taps him on the shoulder again, more gently this time. "We're going to have a proper memorial for him."

"The very best," Tony promises, knowing that across the world billions of such ceremonies are already being planned and hosted. "His friends… did they…?"

"Ned is fine, but he's been worried sick about Peter. I guess I have to tell him… I don't know about his girlfriend or the rest of his classmates, though."

"I'll find out." FRIDAY's already on it, cross-referencing the casualty list with Peter's most recent yearbook. There's not enough complied information yet to confirm everyone's safety, but it looks like some members of Peter's club are now gone, along with a fair number of his teachers. Aunt May clears her throat and reaches for a tissue, patting at the streaks on her face. Tony grabs one too and tries to clean himself up a bit. When he surfaces from wiping his face, he notices her looking at Peter's unmade bunk bed with fresh tears welling in her eyes and suddenly he can't breathe again. "I'm sorry," he says, wanting to reach out and comfort her in some way. But he can't make his hands move. She moves for him, reaching out and picking up one of his hands to rest atop hers. They don't need to share any more words to understand one another.

No matter what she makes him say, this was his fault, and nothing can ever erase that stain on his heart.

He doesn't know how, or when, but one thing is certain:

Tony Stark will avenge Peter Parker.