Howard managed to recreate the serum. They sent Bucky to get it.

[to kill for it, and steve can anticipate the other man's immediate concern.]

They made more Winter Soldiers, but they've been neutralized.

[the corners of steve's mouth tug down at that word. it was murder, really, and as much as he was willing to stop them through any means necessary himself, that doesn't make what zemo did right.]

Bucky doesn't know about this, he hasn't lived it yet. [he glances over at steve.] I don't want him to find out about it. He'd just blame himself, maybe disappear for good.