[By now, you'd think Bucky comes attached with an Elsa-distress meter, as he happens to catch a sight of her - not entirely out of pure luck, no, as he was on his way to the trains himself, to go to the museum island, to go talk to the receptionists there in the hopes of finding out whether or not Elsa is doing okay. He's been doing this for a few weeks, now, as he believes (probably quite correctly) that Elsa would be less than happy to see him.
Unfortunately.
So to see her here is a surprise, and even more so is the ice, forming beautiful, almost flower-shaped spreads below her feet as she runs - but the most alarming thing is the tears. It goes against everything he knows of her, and it, above everything else, is why Bucky runs after her, calling out even though he knows it will do nothing to help:]
Elsa! Wait, Elsa, don't go to the forest, it's not safe there! [Formalities be damned when he's too concerned for her.]