He turns on his heel abruptly, either offended by Steve's response to the teenagers or his answer about Widow-- or perhaps just bored of the current plaque they're standing in front of.

Then he jerks to a halt like a dog hitting the end of his leash at the tinny, echoing sound of archive footage being played in one of the other rooms. The sound of marching and buzzing electricity and voices in German underneath the narrator giving brief and extremely edited facts about the 'rogue Nazi science division,' and then the muted roar of a hundred voices saluting Hydra.

The world around him starts to tunnel. His fingers flex, his breathing picks up.