"The Greek Interpreter," one of the adventures from The Memoirs of Sherlock Holmes, is of interest to Sherlock Holmes fans mainly due to its being our first glimpse of Mycroft, Sherlock's older brother. And Mycroft is certainly a fascinating character: described as "absolutely corpulent" by Watson, but with "the sharpness of expression which was so remarkable in that of his brother," Mycroft has, according to his younger brother, "better powers of observation than I." So the tale is notable for its expansion of the great detective's back story. Sadly, as the reader reaches the end of the story, it is profoundly disappointing compared to many of Holmes's other cases. The bad guys get away, and a man is dead. The Greek interpreter of the title survives, just barely.
Therefore, it's no wonder that the writers of the Granada adaptation felt the need to flesh out the plot considerably. As a result, the last ten minutes or so of the episode contain a plot original to the episode, that is frankly rather ridiculous. Sherlock, Watson and Mycroft go running (literally) after the villains, and confront them on a train. The whole thing becomes a "train adventure," complete with the violent death of one of the baddies, a smooth bit of pocket picking by Mycroft, and even a moment where Mycroft holds a pistol to the other bad guy's head. One gets the distinct impression that the writers knew the ending as Doyle wrote it was worthless, so they just took a sharp turn, and wrote the adventure they wanted to see the main characters have.
Still the episode is not completely worthless. Charles Gray does an admirable job as Mycroft. (My impression was that he was too old to play the role, but I see from a quick Wikipedia search that he was only 5 years older than Brett.) I don't know that Gray was quite as "stout" as Watson describes him in the story, and he doesn't seem nearly tall enough. However, considering the trend in many Holmes adaptations for a slim Mycroft (BBC Sherlock, Elementary, and Enola Holmes spring to mind), I think the casting was pretty good. And we are treated to a lovely scene at the Diogenes Club, wherein Sherlock and Mycroft trade deductions about a random guy in the street below, to Watson's very clear delight.
Speaking of Watson, I am always impressed by David Burke's Watson. I only wish that he had been able to continue the role after this first series. Edward Hardwicke was very good, too, but Burke was the best, in my opinion. Indeed, if I had to rank all the Watsons I've seen over the years, I believe David Burke would be at the top of my list. It is also important to remember that, at the time, Burke was a breath of fresh air for a role that had been largely defined by Nigel Bruce's comic portrayal of the character.
Overall, in "The Greek Interpreter," we are left with an episode that is enjoyable enough for its character development, but that inherits many of the defects of its source material, and tries to over-compensate with a new ending that borders on the ludicrous. So, not a complete waste of time, but not one of the better episodes I've seen thus far.
Postscript: The Nashville Scholars of the Three Pipe Problem, the Sherlockian group in which I participate here in Nashville, TN, just discussed this story a week ago at our monthly meeting. Many of the opinions I've shared above (about the original story and its adaptation by Granada) were voiced by other members of the group. Indeed, we had a lively discussion about the story. And a good time was had by all...
I'm a stay-at-home dad, and Director of Music Ministries at a United Methodist Church in Mt. Juliet, TN, and a longtime fan of Mr. Sherlock Holmes.