Some of the students almost don't obey Steve; after all, he's just another pupil like they are and he's hardly the most commanding sort of guy. But the rest of them, and the teacher, make sure everyone is gone. They're the smarter ones, who have figured out that there's something bigger going on here, and staying won't be helpful to anyone.

Bucky is shaking like a leaf in high winds and his eyes are half unfocused, as if panic is driving him out of the here and now and into somewhere else. He made himself vulnerable, separated himself from his weapons and showed his weaknesses and--- He lets out something halfway between a sob and another plea of Steve's name.

Penny decides enough is enough and lunges to bite Steve on his wrist to try and make him let go. Not a hard bite, she's trained not to break skin or injure, just a sharp shock. It's seeing his dog go for Steve that helps to pull Bucky towards reality again, and he mumbles the command for her to stand down before he basically collapses on Steve's shoulders, sobbing as if he might break.