[Or maybe it'll still happen, just somewhere else. Because that's just how much the future wants to kick you in the balls repeatedly, Bucky. Not that Sam's too happy about it, either - at least, not about telling him.]

Nah, he shot them all in the head while they were still under. The important part was to get Steve and you and Stark to Siberia. See, this asshole, his family died in the battle of Sokovia, and he blamed the Avengers. Never mind that his city had been, you know, raised into the air by a genocidal robot who was going to drop it from a mile up and kill everyone in Europe, he wanted to wreck Steve and Tony personally. And somehow, he found out about one of your missions, and that Steve was keeping a real big secret from Tony.

[It's hard to remain calm when he sees Bucky tense up; some primal instinct in Sam wants to prepare to defend himself in case he loses control. But he just keeps sitting there like everything's fine and he isn't marginally worried a super-soldier's going to beat the shit out of him.]