"I don't know," says Sherlock. It occurs to him that six months ago he might have said no with more certainty, or something with more certainty, at any rate. Today he just levels Jeremy Fischer with a frank, serious look. "It could be. I think it's virtual reality, but I don't have a fine enough understanding of programming," he waves a hand to indicate, or whatever you call this, "or neurobiology, for that matter, to know if that's feasible or how. It's very realistic. Not entirely, but extremely. And you'll find things that--"

He hesitates to say break the laws of physics, because he loathes that phrase. The term 'laws' is misleading in the subject of physics: people are always gleefully talking up the possibility of 'breaking' the laws of physics left and right when of course, there's no such thing. Any observed violation of physical laws only proves that they were in error, or that your observation. Sherlock tries to remind himself of that: either they were in error or you were. No one is incapable of being tricked, not even you, Sherlock Holmes.

He summons a smile, an ironical, chilly one--if nothing else, he can make a show of good humor for this American. "You may find it all a bit new," he says.

It's getting colder as the sun dips lower. Sherlock has noticed that the Extras are thinning out for the day. Prime busking hours are over. He kneels and starts to pack up his case. "Can you cook?" he asks Jeremy, apropos of nothing.