"The bit of your style that isn't Sherlock is very weird," she comments.

"Is it? How?"

"Mmmm... Doesn't react normally to being boxed in."

"That's me, all right."

"It's half of you, at least."

"And your boyfriend's the other half, I suppose? Interesting way of looking at it."

"You do seem in some ways a cross between my boyfriend and a God-knows-what. 'Nother round?"

"Hang on, give me a second, I'm gonna upgrade my autopilot," she says, and she goes to where she dropped her bag and pulls out a notebook.

"Upgrade your...?"

"So, when one starts being the Slayer, one gets fancy combat instincts, but these instincts are highly compatible with learning new things, and I like to do that via notetaking for unrelated reasons."

"Aha. And now you are teaching yourself how to adapt to me," he says. "I expect I've still got a surprise or two left in me, even so."

Mark is vastly outclassed in raw physical terms, and the advantage lent by his assassin training dwindles with time, but he retains his edge in... call it lateral thinking. Disrupting patterns, foiling expectations.

"Anytime."

"Well, not literally, I don't think we're that mutually accessible under normal circumstances."

"Granted."

"You seem so disappointed."

"People who can beat me up when I'm trying are a rare resource."

"...Mm?"

"When I met Sherlock he was coasting along the edge of suicidality out of boredom, and then I proved very interesting, and now he's not. Wondering whether your life is lively enough to suit you."

"I think I'm self-sustaining on that score," he says. "I have different problems, and mostly not ones that make me likely to kill myself."

"Okay. ...Do you want to tell me about your problems?" she inquires, collecting her bag and heading back into the bar.