He forgets to close the door.
Close the door, John says (growls) in his ear. Or were you born in a barn?
“Sorry,” he mumbles, then closes the door. Locks the door, too. Both doors (living room and kitchen), they’re closed and locked now. Just wouldn’t do to have Mrs. Hudson traipsing about with tea and biscuits. Or whatever it is she does these days. (He doesn’t know, doesn’t care.) Maybe she’s responsible for the tea that turns up every morning. (He drinks it because John isn’t here to make him tea anymore.)
Took you long enough.
Just a voice, and it’s almost too much for him. Better than seeing the disappointed look on John’s face.
What did I say? Merciless. Giving him no room to breathe. The coin bag in his pocket weighs as much as an ice pick meant for caving his skull in. (That’s the point.) What did I say, Sherlock, about the next time you decided to do something like this?
“You said that you would leave,” he replies, unable to forget that. Right before the Baskerville case: a largely harmless dalliance with cocaine led to him quit smoking cold turkey in order to please John. Demonstration of his sincerity: I’ll give up anything for you, John. Even the nicotine. “You said there would be no point in staying if I didn’t stop with the drugs.”
“But you’ve already left me.”
And now look at what you’ve gone and done to yourself.