The first time he doesn't know why they come for him.
He knows their technology is still a little bit dodgy, they're still working on smoothing out the kinks that come with trying to rewrite a human brain like a computer, but they're sure they're getting there and Bucky – if that's still who he is, because he really can't be sure anymore – hasn't given them any incentive to believe otherwise. He doesn't need anyone telling him that would be dangerous.
The first time they come for him, he's in his cell, strapped down because they're still not quite sure what he's capable of in this state of in-between-ness that they've put him in. He might be dangerous, or he might be their most loyal lapdog. He might be trying to slip out of their grasp.
It's dark in the cell, the stench of metal is overwhelming even after all these weeks – months? – but he's fallen into an unrestful slumber nonetheless. That's all he can do now, take his chances while he can and isn't that something, he used to be the one who took the initiative, who never backed down and now he's left to deal with the scraps. Deal with the scraps of who he used to be.
The first time they come for him the door bangs open with a start, and his reflexes tell him to sit up where his body is still tied to the mattress. He stares in horror and the man towering over him.
Knows, without a doubt, what is coming.
The second time they come for him, he wakes up a split second before the door bangs open, and feels unhinged. They'd tried wiping his mind blank once again that day, and it had held for a solid ten minutes before everything came crashing back into him with a painful intensity, left him howling and screaming and begging for it to end, but what was worse was the memory of that blessed nothingness, and then the realisation that this was what they'd make him into if they could. What they would most certainly make him into one day.
He's still shaking with the recovery – my name is James Buchanan Barnes, I live in Brooklyn, New York, I – when cold metal hits concrete and there's the man again, a giant outlined by the cold light of the corridor. Bucky thinks of blond hair, and then pain.
The third time they come for him, he's figured out what he's been doing wrong, and he hates himself for it.
He'd seen the recording that day when they thought he was still passed out from another mind-wiping session, and when he resurfaced there was the face of a stranger on a computer screen, screwed up in pain, glistening with sweat, lips whimpering the name Steve over and over again. The stranger was sleeping, but it wasn't a very restful sleep.
Later in his cell, he puts the pieces together, he figures the stranger must have been him because he knows Steve, feels like he will know him to the end of the earth but the truth is that his face is already evading Bucky's memory, and he's lying on the thing mattress with empty hands and an aching head and only the echo of what must have been his best friend. He can't really remember what Steve was to him. What he wanted him to be.
He goes to sleep that night, careful to put all thought of Steve aside, and when they come for him it's not to inflict more pain.
Instead, they put him in the chair in the middle of the night, tie the straps and boot up the machine. Bucky things the timing a bit odd, but it's better than what they used to do with him in any case. He can almost deal with the jigsaw puzzle his memory becomes after the sessions.
(When he wakes the next morning, he's blessedly refreshed and surprisingly not in pain. There are dark bruises on his wrists and hip. He observes them with a detached curiosity, moves his flesh and metal hands slowly. When he walks, his feet fall clumsily. He doesn't wonder, doesn't think, just lies there breathing slowly. There is nothing on his mind.)
(He never wakes at night with the name Steve on his lips again.)