The Greek Interpreter

Holmes's brother Mycroft only ever turns up at Baker Street when something genuinely odd is happening, which is how the story of Mr Melas arrives. Melas is a Greek interpreter who was seized and taken to a house he could not identify. There he was ordered to translate for an injured Greek man he had never met, and the translation was part of a threat. He escaped, and the story he brought back was strange enough for Mycroft to take it to his brother. The man at the centre of it, Paul Kratides, was still missing. It is the one case in which Holmes's family gets involved, which is reason enough to pay attention.

Holmes works out the shape of it quickly. Two villains, Harold Latimer and Wilson Kemp, had kidnapped Kratides and were trying to force him to sign a document that would release his sister Sophy to marry Latimer. George Costigan and Nicholas Field make a properly unpleasant pair of them. Anton Alexander's Kratides and Victoria Harwood's Sophy are the two at the mercy of the scheme, and Alkis Kritikos as Melas gives the episode its frightened, indignant centre.

Charles Gray debuts here as Mycroft, and he makes the part his own. It is a nice bit of casting luck that the actor who would become the definitive screen Mycroft arrived in the story that introduced the character to the canon. Alan Grint directs, with the script by Arthur Conan Doyle, John Hawkesworth and Derek Marlowe. Oliver Maguire and Rita Howard fill out the supporting cast. Michael Cox produced, with music by Patrick Gowers and cinematography by Michael B. Popley.

But the title is the point. Everything in the episode runs through interpreters, through men who cannot say what they know in the language they know. It makes the mystery one of the most awkward and interesting of the series, a puzzle where finding the criminal is easy compared with getting anyone to say anything straight.