Bucky stiffens, breathing harden than he has any right to without exerting himself at all. He hates the damned logic behind Sam's words, when everything in him is screaming for an outlet to act. He hates Steve for telling him not to come for him.

"They already caught us once. Two times?!" he shakes his head, then snarls in frustration and lashes out with his fist against the wall again.

It's after that he crumbles, shoulders slumping to shake with helplessness. "I'm supposed to protect him, I shouldn't have left. I should have stayed."