Sherlock, on the other hand, takes in the faint scent of cheap perfume and the hint of a red line peeking out from under a cuff and very deliberately puts down the bottle so as not to be tempted to use it as a weapon.

"Good evening," he says coldly. "You might try being more discreet about your little hobby. If the other Sherlock sees those marks, he is unlikely to give you the benefit of the doubt."