I may be late to the party on this one, but I just noticed something from the restaurant scene in ‘A Study In Pink’…..

Sherlock, you sly devil. You made reservations. You’re in the middle of the case and you made dinner reservations. For John.
Now we know why Angelo was so quick to assume John was his date.
For John
Sherlock HolmesDear John,
I wish you well.
That is the best way to begin a letter like this, I suppose. The ceremony was lovely, and much to my delight, not too long. You’ve a great deal of friends who could not be more pleased for the two of you.
Mary Morstan is a tolerable woman, and clearly makes you very happy. So my wedding gift to you is a song. I wasn’t intending to get you a gift at all, but Mrs. Hudson was quick to inform me that it was ‘bad manners’.
So I enlisted her help. I have recorded a personal composition of mine for you to listen to at your discretion. It was composed with you in mind, and as you may recall, was played many evenings when you woke from the throws of a nightmare. It’s purpose was to soothe you whenever you were upset or agitated.
I hope you will turn to this song when you find yourself unhappy or uneasy. Mrs. Hudson assisted me with the recording; she was quite an excellent piano player in her day, and was more than happy to accompany me in the piece.
Give my regards and well wishes to your new Mrs. Watson, and believe me to be, my dear friend,
Very sincerely yours,
S. Holmes
[actual song is ‘Barcarolle’ by Offenbach, of course, but when listening to it, I always imagined it would be the kind of song Sherlock might compose for John]
