His memory flicks back, unbidden and with such clarity that he can almost imagine the scent of blood streaked on his face again, of the rock in both hands as he brings it down again and again and again on the widow's head. At the urge to vomit that he'd swallowed down in the face of John's own horror.

His jaw sets, a vicious working of muscle as he looks away from Bucky, his hand gripping the grab handle until he's white knuckled.

"No," he says, and there's gravity to it, a threat for if Bucky challenges that. "I wouldn't."