Steve, of course, has no fricking idea what's going on. All he knows is that Bucky seems to have gone a little -- unstable. Which is not good. Part of him is suddenly, seriously angry with T'Challa, who isn't even there because they were supposed to fix his best friend's memory problems. Part of him is also despairing because if Bucky wasn't fixed that means this can happen again and he's fucking tired of losing the other man. But the majority of his emotions are now caught up in a bundle of worry. Worry for Bucky. Worry for anyone who might stumble into this mess.

"You knew me earlier," He says, trying to keep the alarm and misery out of his tone, trying to project a measure of centered calm. "Tell me what happened. I won't get mad. I promise." What he means is - he won't get mad at Bucky, specifically.