There’s something so powerful about the end of this episode. We learn that Sherlock can be surprised, that he does learn about a human being as he goes-that his first deductions about John covered where he was and his situation and family but not WHO he was; that there is something more to John Watson-there will always be more to John Watson. The most fascinating aspect of a case, forget about the perfect locked room mystery. And that whatever this feeling-this bond-between them is, even if it does strangely ring of sentiment-this, this is worth keeping. Better than the skull, in any case.
The moment when Sherlock realizes his Prince is real and has finally shown up in his life.