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 Sherlock Holmes and Irene Adler. He appears in two pastiche novels by author John Lescroart, "Son of Holmes" (1986) and "Rasputin's Revenge" (1987). Lupa, a secret agent during the First World War, is strongly implied to be the younger version of fictional detective Nero Wolfe in the mystery series by Rex Stout. Enola Holmes is the younger sister and youngest sibling of Sherlock and Mycroft Holmes. She appears in the series "The Enola Holmes Mysteries" by Nancy Springer and it could be inferred that she appears in the story "The Copper Beeches" as Violet Hunter, however there is not enough