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.
Gentleman detective detective sergeant in the Metropolitan Police's [fictional] specialised task force, SI 10, and finds herself partnered with (and subordinate to) working-class NYPD Lieutenant James Dempsey who is on extended loan to the Met. Gentleman detective The gentleman detective is a type of fictional character. He (or, less commonly, she) has long been a staple of crime fiction, particularly in detective novels and short stories set in Britain in the Golden Age. The heroes of these adventures are typically both gentlemen by conduct and also members of the British gentry. The literary heroes being in opposition to professional police force detectives