"You're clever," Moriarty says, standing up.

The cravat comes off first, set on the back of his chair. Then, a little more shyly, he unbuttons and strips off his shirt. Last go his trousers, dropped to his ankles and stepped out of while Moriarty looks like he might just about explode into a cloud of embarrassment on the spot.

In defiance of all logic, he looks down to check that his underwear hasn't vanished into the night when he wasn't looking.