One of the funniest scenes in the whole show, Sherlock Holmes finds himself in Buckingham Palace, wearing nothing but a sheet to be greeted by Mycroft. From suggesting his brother is the Queen to revealing to John that he's not wearing any pants, it's an amusing scene from start to finish, climaxing in his deduction that the Equerry's "employer" is a smoker. "We have kept a lot of people successfully in the dark about this little fact, Mr Holmes", he remarks. "I'm not the Commonwealth," comes the reply. Of course, it should make sense for such a British icon appearing in Buckingham Palace to be such a great moment of television, shouldn't it?
