The Adventure of the Mazarin Stone

Plot

Watson arrives at 221B Baker Street where the page boy Billy shows him a wax effigy of Holmes placed near a curtained window in the sitting room. The effigy produces a shadow on the curtain that, when viewed from outside, is the unmistakable profile of Sherlock Holmes. Using this visual trick, Holmes aims to give a perfect target to a would-be murderer with a rifle. Holmes names his murderer as Count Negretto Sylvius, the diamond thief he has been following in disguises. He gives the criminal's address to Watson, then sends the doctor out the back for the police. As the Count arrives, Holmes has Billy invite him inside, then takes him by surprise when he attempts an assault on the effigy. Holmes then offers the Count and his helper, boxer Sam Merton, freedom if they give up the jewel, or jail if not.

He invites them to discuss the deal while he plays violin in the next room. When the Count decides to double-cross Holmes and takes the stone from his secret pocket to show Sam in window light, the detective springs from the chair in place of his replica and grabs the £100K jewel. His bedroom has a gramophone and secret passage to behind the curtain.

After the police take away the villains, Lord Cantlemere sweeps in. Unlike the Prime Minister and Home Secretary, he did not want Holmes. When tricked into insisting on arrest for whoever is found possessing the diamond, he finds the jewel in his pocket - where Holmes has placed it - and apologizes. Finally, Holmes can eat.

Unusual aspects

It is notable for being one of only two Arthur Conan Doyle Holmes stories, aside from a couple of humorous vignettes, to be written in third person. The other is "His Last Bow". "The Mazarin Stone" was written this way because it was adapted from a stage play, "The Crown Diamond", in which Watson hardly appeared. Its adaptation from the theatre also explains why the action in this story is confined to one room. The plot twist in which Holmes reveals he had been listening to the two criminals as they spoke freely would also not have been possible using a first person narrative.

In the original play, the villain was Holmes's enemy Colonel Sebastian Moran of "The Adventure of the Empty House" infamy, not Count Negretto Sylvius.

In other media

The 1946 film Terror by Night uses some motifs from "The Mazarin Stone".

This story was heavily rewritten for Granada Television's Sherlock Holmes series. In 1994, it was merged with another story, "The Adventure of the Three Garridebs". The most noticeable change is that Holmes does not feature except in the prologue and final scene (actor Jeremy Brett was away due to illness). It is Mycroft Holmes (Charles Gray) who takes up the case of the stolen diamond, while Watson is retained to look into the Garrideb mystery.

"The Adventure of the Headmaster with Serious Trouble", an episode of the NHK puppetry show Sherlock Holmes is an adaption of this story. In it, Holmes puts his dummy near the window and searches for the stolen love letters of Headmaster Ormstein despite being suspended from going out because of breaking school regulations.

Adaptations

"The Mazarin Stone" was dramatised for BBC Radio 4 in 1994 by Bert Coules as part of his complete radio adaptation of the canon, starring Clive Merrison as Holmes and Michael Williams as Watson, and featuring Anthony Bate as Lord Cantlemere and Nigel Anthony as Count Sylvius.