Tony and Bruce had been working in silence for some time. Tony's underground train of thought finally surfaced and he began, absentmindedly, to think out loud.
"Could the other guy survive under water? Like, go deep sea diving without scuba gear? ...That would be a good place to hulk out. Wouldn't have to drive so far. There's nobody to hurt. He can't be hurt, so he can't drown can he? But he doesn't have gills or anything. ...Well, nothing about the big green fits with the laws of nature or physics or anything... so never mind."
All of this was said as he tinkered with a machine, not once looking up. He did not notice Bruce stop typing or his expression furrow with a mix of guilt and pain. Tony, however, did look up when his brain caught up to his mouth and he realized he might like some feedback on that musing. Bruce was zoned out, momentarily in another place and time. That look was still on his face. Tony's own face fell.
"Oh no."
"What?" Bruce asked, his attention suddenly snapped back into place.
"Don't tell me you tried that too." Tony groaned, his voice tinted with sorrow.
Bruce looked down for a second and then back up at Tony. He shrugged his shoulders.
"I was curious about that too." Was all he said.
Tony and Bruce stared each other down for a moment. Tony held his friend's gaze until smiles suddenly broke out on both their faces. Tony balled up the nearest piece of paper and threw it at Bruce's head.
"F**k you, Banner, for being so at peace with your past."
Dodging the paper ball, Bruce gave a sarcastic snort.
"More like resignation. I can't change it now, so why be sad."
"Exactly. Peace." Tony said.
Bruce silently nodded, half convinced, and looked back at his computer screen. He did not see the look of fond admiration on Tony's face. Bruce had no idea how strong he was. With that thought, Tony went back to work on the machine