Yelena nods slightly. "O.X.E. decided they wanted to make their own superhero. The study they recruited you for, and others like it in other parts of the world, was their way of recruiting test subjects for their methods. They scrapped the project as a failure, and sent us in to clean up any traces. I don't think Valentina even knew it worked on you until you got shot about a hundred times and didn't die."

Or maybe he had died. She'd seen the footage Bucky had pulled from the surveillance system; he'd been down long enough for Mel and Valentina to walk away. Resurrection isn't out of the question.

"She brought you here after you crashed, to the lab. To pick up where she'd left off with her Sentry project."