Introductions
"Are you alright?" That's honest concern John can hear in Sherlock's voice. Thus dies 'sociopath' still-born. "You have just killed a man."
John would like very much to dodge this bit. If there's anything more awkward than killing someone, it's talking about it. But Sherlock refuses to be put off, and he's not just guessing. What he is doing is watching John and talking to him like they're the only two people in existence. In the middle of a crime scene surrounded by about fifty policemen, of whom the closest is Lestrade himself, the ferocity of Sherlock's attention falls around them like a privacy curtain, denying the existence of anything beyond its boundaries.
John feels like he's in a confessional. This expression Sherlock's turned on him, a man might tell it anything, if he were mad enough to trust the mind behind it.
"That's true," John admits after a moment, stepping into that room built for two and closing the door behind them.