Max Carrados and his usual accomplice, Mr. Carlyle, are introduced in the first story, "The Coin of Dionysius." Carlyle is a private investigator, running a private inquiry agency concerned mainly with divorce and defalcation. He is directed to Wynn Carrados for an expert opinion on a tetradrachm of Dionysius the Elder of Sicily which he believes may be a forgery. At their meeting, the blind Carrados immediately recognises Carlyle from his voice as his former schoolfriend, Louis Calling. Carlyle then recognizes him in turn as Max Wynn.
Max explains that he was made financially independent by a rich American cousin who left him a fortune on condition that he adopt the surname Carrados. He was blinded some twelve years before the first story as a result of an incident while out horse-riding. Carlyle, a former solicitor, was struck off for his supposed involvement with the falsifying of a Trust Account. After this scandal, he changed his name and set up the inquiry agency.
Carrados enjoys revealing his explanations of mysteries through powers of perception, which ought to be at the disposal of any sighted person, but which in his case are heightened in positive compensation for his visual impairment. Given the somewhat outlandish idea that a blind man could be a detective, Bramah took pains to compare his hero's achievements to those of real life blind people such as John Fielding the Bow Street Magistrate, of whom it was said he could identify 3,000 thieves by their voices, and Helen Keller.