The sound Thor makes cuts straight into him, making Steve almost flinch at the intensity of such a sound coming from his teammate, from someone he considers a friend in some right. It increases his hatred of the Capitol even more to have their torture and torment last so long after the deed is done. He already had hated them so much for how they altered the man, but this just adds to it even more.

He wants to approach the other man, but he thinks better of it, knowing how well that worked out for him the last two times he dealt with brainwashed people. Which was, not very well.

But it's when the other man goes still, oddly calm, that Steve goes on his guard again. Something instinctively inside him says that at this moment, Thor is completely unpredictable, he might run, he might fight, but it still puts Steve into a deep unease. It makes him hesitant to even speak, knowing making a sound could set him off, knowing the wrong words could alter the situation irreversibly, but they could also help. The right words could reach him.

Right?

"Please, more blood on your hands won't do you any good," the words are more a whisper, enough for the man to hear, something soft, more like he's talking to a wild animal that needs soothing than a man.