Sherlock blinks, straightening even more. He's comforted Watson before, but never when she's been this deeply upset, in part because she never gets this deeply upset. But he collects himself and nods, rising and heading upstairs.

He enters the dark room and sits on the bed next to Watson. He hesitates for a moment...then he reaches out and takes her hand. Joan looks up at him. He's never done this before, being generally uncomfortable with touch and physical affection. And yet here he is, initiating touch. It warms her. She doesn't squeeze, not wanting to scare him off, but she does curl her fingers around his.