Tony's hiding in the vents.
Jarvis having stayed infuriatingly silent, Clint is searching from the other end; it's Pepper, therefore, who finds him. He's curled up in the foetal position, as small as a small eleven-year-old can be, and his breathing is erratic enough to alarm her.
"Tony," she whispers, pulls his shivering frame into her arms.
He flinches, struggles away and retches miserably, silently, bringing up nothing but water and bile. She reaches for him once it's over, slowly, carefully easing him towards her; he comes willingly enough, but he's crying.
"Tony," she says, wiping his cheek with her thumb, "what's wrong?"
He says nothing.
The tears won't stop.
"Why are you here?" she tries again, and his face instantly crumples.
"I couldn't," he bursts out, sounding utterly wrecked, "I can't, you'll all be mad, you - I couldn't, I didn't want to make more trouble, I'm already enough, and Stark men are made of iron - " he swipes his sleeve across his eyes, but it makes no difference to the tears. "I'm - I'm sorry, I made a mess, I'll clean it up, you don't - have to worry - "
"Tony," she interrupts, shocked despite herself, "you don't have to do anything except tell me what's wrong."
"Don't - don't be mad, Miss - Miss Pepper - " she can feel his resolve crack with his voice, and who'd have dreamt Tony Stark was such a painfully polite kid, even when he was sobbing brokenly into an adult's lap - "Miss Pepper, I hurt, please, please make it stop."
"Nobody's mad at you, Tony," she says, stroking his sweaty hair and panicking, has he been poisoned, why is he hurting enough to cry, "just tell me where you hurt."
"My head," he chokes out, and suddenly it all makes sense.
Her hand must have stilled in his hair at the thought; he looks up with an effort, tears continuing to spill from his eyes.
"Am I dying?" he says with that damn eleven-year-old gravity, and Pepper, for once, is struck utterly speechless. "Miss Pepper, am I dying, I don't know, I can't remember, I can't solve, I don't - know anything, anymore."
Well, aren't you the same old heartbreaking rambler.
"You're not dying, Tony," she finally manages. "You're coming downstairs with me and we're getting some medicine into you, nobody's mad and nobody is dying today, is that clear?"
"Yes, ma'am," he whispers, and she has herself an armful of shuddering child.
"I'm sorry," he says again into her shoulder, and she holds him tighter and kisses his hair.
(They give him children's doses of Tylenol and ibuprofen, tuck him with a heating pad under the softest blankets they can find, switch off all the lights there are, watch his angelic sleeping face, and resolve to hug his adult self close the moment they get him back.)