As far as Bucky's concerned, he's straight out of a war zone. Instinct pushes him to the ground the instant the explosion hits, though he doesn't stick around for long. With the fire out, it's clear enough that it's an isolated incident. Brushing off his hands, he springs back up to his feet, inching closer to see what the hell that powder was before tossing Tony a look.

"I thought you were a doctor," Bucky says on the edge of a breathless laugh, shoving a hand back through his hair. "This what you do on your own time?"