The Adventure of the Greek Interpreter Sherlock Holmes, far from being a one-off in terms of his powers of observation and deductive reasoning, in fact has an elder brother whose skills, or so Holmes claims, outstrip even his own. As a consequence of this, Watson becomes acquainted with the Diogenes Club and his friend's brother, Mycroft. Mycroft, as Watson learns, does not have the energy of his younger brother and as a consequence is incapable of using his great skills for detective work: In spite of his inertia, the elder Holmes has often delivered the correct answer to a problem that Sherlock has brought to him.
Minor Sherlock Holmes characters evidence to support the idea. Enola is a very independent and rebellious girl who likes to wear trousers while riding her bike. She becomes a Perditorian, or finder of lost things, when her mother runs away with the gypsies and her brothers try to send her to boarding school. Using her natural cunning which seems to be inherited by every member of the Holmes family, she creates multiple disguises on her quest to be reunited with her mother and evade her brothers. A third Holmes sibling appears as a reference by Mycroft in the BBC "Sherlock" series, in the third-season