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.
Jack Spratt (fictional detective) fabricated. It is revealed that early on in Spratt's career, his ambitious and self-obsessed partner Friedland Chymes stole most of the credit for their greatest cases, thereby rising to the top to become one of the most popular detectives in England. Jack, being totally honest and unwilling to cater the media's demand for glamorous hero detectives, was unable or unwilling to stand up for himself; Friedland and Jack have been enemies since. However, as the story progresses it becomes clear that Jack is not only honest, but highly intelligent and a much better detective than Chymes. Spratt is a Detective