On November 21st…

November 21, 1895: Mycroft asked Holmes to find the stolen submarine plans. [BRUC]

‘[…]Every effort has been made to keep the secret. The plans, which are exceedingly intricate, comprising some thirty separate patents, each essential to the working of the whole, are kept in an elaborate safe in a confidential office adjoining the Arsenal, with burglar-proof doors and windows. Under no conceivable circumstances were the plans to be taken from the office. If the Chief Constructor of the Navy desired to consult them, even he was forced to go to the Woolwich office for the purpose. And yet here we find them in the pockets of a dead junior clerk in the heart of London. From an official point of view it’s simply awful.’

‘But you have recovered them?’

‘No, Sherlock, no! That’s the pinch. We have not. Ten papers were taken from Woolwich. There were seven in the pockets of Cadogan West. The three most essential are gone – stolen, vanished. You must drop everything, Sherlock. Never mind your usual petty puzzles of the police-court. It’s a vital international problem that you have to solve. Why did Cadogan West take the papers, where are the missing ones, how did he die, how came his body where it was found, how can the evil be set right? Find an answer to all these questions, and you will have done good service for your country.’

November 21, 1901: Holmes wrote to thank Morrison, Morrison and Dodd for their letter about vampires. [SUSS]

BAKER STREET,
Nov. 21st.
Re Vampires

Sir,

Referring to your letter of the 19th, I beg to state that I have looked into the inquiry of your client, Mr Robert Ferguson, of Ferguson and Muirhead, tea brokers, of Mincing Lane, and that the matter has been brought to a satisfactory conclusion. With thanks for your recommendation,

I am, Sir,
Faithfully yours,
SHERLOCK HOLMES

Source: A Day by Day Chronology of Mr. Sherlock Holmes according to Zeisler and Christ, compiled by William S Dorn, BSI, DWNP