King of blackmail - S1.E1

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.