" Mycroft Holmes: ...a necessary evil, not a dragon for you to slay. Sherlock Holmes: A dragon slayer? Is that what you think of me? Mycroft: No... It's what you think of yourself. Mrs. Holmes/Mum: Are you two smoking? Mycroft: No- Sherlock: It was Mycroft! (They hide their lighted cigarettes behind their backs.) -Sherlock, "His Last Vow", season/series 3 "