Sherlock's brow creased slightly at the man's expression. Fear. Oh, yes. Closeted society. Possibly while homosexuality was a capital offence. History mattered very little to him, in general. Specific crimes and problems he knew in detail, of course. But in general it was utterly pointless.
"Oh, don't worry," he said. "It's obvious, but only to me. No one else would suspect a thing."