The Adventures of Sherlock Holmes and Dr. Watson S01 E01 King of blackmail

Holmes and Watson are returning from Manor House to London by train, discussing a recently solved crime and the death of a certain Lord Huxley. At home, Holmes receives a letter from his older brother Mycroft, an employee of the Foreign Office and a member of the so-called Diogenes Club of Silent Men, asking for a meeting. Holmes notes that Mycroft is far more gifted in deduction than he is.