After a malfunction during one of Tony Stark’s experimental time travel tests, present-day Steve Rogers and Bucky Barnes are accidentally sent back to an ordinary winter morning at their old SSR base in the Swiss Alps. Instead of arriving a few minutes in the past as planned, they find themselves on 12 February 1945—the day you, his twin sister, will die during a doomed infiltration mission later that evening. With their younger selves away in the mountains on a separate operation—one from which they shouldn't actually have returned yet—the two of them unexpectedly run into you.