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6 Classic Sherlock Holmes References to Look for in "The Sign of Three"

6 Classic Sherlock Holmes References to Look for in "The Sign of Three"

Sherlock. In anticipation of the U.S premier, we’re brushing up on our Sir Arthur Conan Doyle and looking for the wonderful literary nods in everyone’s favorite TV adaptation of the famous detective. Of course, the title of the episode—“The Sign of Three”— refers to the second Sherlock Holmes novel titled The Sign of the Four (or sometimes just The Sign of Four) in which John Watson meets Mary Morstan, who becomes his wife. Some of the same stuff happens here, but there are a few other references. Here’s six we caught.

Sherlock’s Quote About Romance

In giving his best man speech, a nearly exact version of something Holmes says in the original The Sign of the Four is recreated here. It’s easy to guess what Holmes thinks about love, and though the context this time is totally different, the content is pretty much the same. Here’s the original quote: “But love is an emotional thing, and whatever is emotional is opposed to that true cold reason which I place above all things. I should never marry myself, lest I bias my judgment.” But does our Cumberbatch/Holmes truly feel that way these days?

Holmes Knows Ash!

During a particularly memorable scene in this episode, Sherlock declares proudly that he “knows ash!” This references the fact that Holmes has penned a monograph on the subject of tobacco ash, first mentioned in A Study in Scarlet. Holmes uses this skill-set to figure it all out in The Hound of the Baskervilles and The Valley of Fear. This reference might also refer to the real-life Sherlock Holmes fan society The Adventuresses of Sherlock  Holmes (ASH for short), a scion of The Baker Street Irregulars, which was founded by female fans of the great detective, since the original Irregulars didn’t originally allow ladies!

A Small Man With a Blowgun

In the main climax of the novel The Sign of the Four, Holmes and Watson are embroiled in all-out chase with Tonga, a small islander adept at shooting darts from a blowgun. In two different ways, this small assassin is referenced in this episode. Once, in an outright flashback to a previous case, and again, in subtler way. As in “The Empty Hearse,” the writers of Sherlock seem to love referencing certain plot elements more than once.


In the original The Sign of the Four, the late Major Sholto is a big focus of a plot involving missing/stolen jewels. Here, Sholto’s association with John and Mary is slightly different, and his role almost totally inverted from the original story. However, he is still a military man.

Sherlock’s Knowledge of Current Events Is…Non-Existent!

In one scene, Sherlock makes a reference to “the current King of England.” John reminds him that England doesn’t currently have a king. This seems like the ongoing reference to Sherlock Holmes’s weaknesses on certain areas of knowledge.  John Watson draws up a list of Holmes strengths and weaknesses (which is super revealing of what he’s ignorant of) in A Study in Scarlet.

A Hollow Client

There are so many quick references to cases this Watson and Holmes have experienced but that we haven’t seen, it’s hard to pinpoint all shout-outs to original Conan Doyle stories, but when “The Hollow Client” is mentioned it may be a reference to “The Empty House” where a dummy of Sherlock Holmes is used to evade Col. Moran. However, because of the role a fallen military man plays in this episode, this might also refer to “The Adventure of the Blanched Soldier,” whose features could be described with a different definition of “hollow.”

What references to classic Holmes stories did you catch?

Tags: shows we love, bbc, benedict cumberbatch, martin freeman, sherlock, watson

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About the Author
Ryan Britt

Ryan Britt is the author of Luke Skywalker Can't Read and Other Geeky Truths, forthcoming from Plume (Penguin) Books on 11.24.15. He's written for The New York Times, Electric Literature, The Awl, VICE Motherboard, Clarkesworld Magazine, and is a consulting editor for Story Magazine. He lives in New York City.

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