Or, if you prefer, ‘The Sign of Four’, which is I think the better known version of this novel’s title. There is quite a significant difference between the former – meaning a sign which collectively represents four people – and the latter, which means simply 4. But as the sign itself plays no real part in the plot, other than contributing to the overall effect of mystery, the point is moot.

A quick plot summary might be a good place to start. This is an early Holmes story, where many of the familiar tropes of the sequence are just being established. Here we see the first incarnation of Holmes’ famous, if nonsensical, epithet “when you have eliminated the impossible, whatever remains, however improbable, must be the truth”. (140) We see Holmes, bored, and taking cocaine – a 7% solution – which he also offers to Watson. The method whereby Holmes is able to make fantastically accurate deductions about people from minor aspects of their appearance and behaviour is used at the opening of the novel, serving little purpose other than entertainment to relieve the boredom, and is disregarded once the crime is under investigation. And of course there are the Baker Street irregulars, the blundering police, and the mastery of disguise. All the elements are here, early on in his career.

The crime itself is, as usual with Holmes and Watson, obscure, yet easily solved. Indian treasure, pillaged from Agra during the First War of Independence, is hidden in a house in the London suburbs. One of the gang cheated out of his share of the prize returns to steal it, and in the course of the burglary someone is murdered. The villains hide on a boat on the Thames, but are chased down and captured. During the chase the treasure is thrown overboard and lost. In a lightly done parallel plot Watson falls in love with, woos, and becomes engaged to be married to the client who brings them the mystery – Watson is quite a fast worker!

Holmes’s powers are not taxed greatly. The murderer leaves footprints at the scene, and a trail of tar from the scene to their hideaway. The murderer’s accomplice has previously been seen shadowing the victim’s father, and leaves marks of his wooden leg outside the window. There is little attempt at concealment or deception. Holmes is slightly delayed in capturing the villains by their cunning ruse of hiding their boat in a boatshed, which it takes a particular genius to discover. It’s all done and dusted in less than a hundred pages, with plenty of time for some light drug taking and observational parlour tricks.

How does one explain the enduring appeal of the Holmes stories? Victorian England couldn’t get enough of the curmudgeonly consulting detective, forcing Conan Doyle to bring him back after the Reichenbach Falls attempt to kill him off. It can’t be the thinly constructed plots. While Holmes and Watson (and Mrs Hudson) may have survived as characters, the novels and stories themselves are little read, and usually discarded in any adaptation. Holmes represents the victory of rationalism and reason against the forces of nature and the threatening world outside our borders. It is hardly surprising that the villains in Holmes’ adventures are invariably foreigners, threatening our great British institutions. Tonga, the Andaman islander with the feet of a child, is described in purely animalistic terms. When first spotted on the boat, he is “a dark mass which looked like a Newfoundland dog”. (178) Closer up he seems to Watson to be a “savage, distorted creature. He was wrapped in some sort of a dark ulster or blanket, which left only his face exposed, but that face was enough to give a man a sleepless night. Never have I seen features so deeply marked with all bestiality and cruelty. His small eyes glowed and burned with a sombre light, and his thick lips were writhed back from his teeth, which grinned and chattered at us with half-animal fury” (178) Only half-animal Watson? Holmes can defeat any puzzle, any challenge, with the application of logic and knowledge. The world can be tamed. The fact that this is all smoke and mirrors, and that the final resolution usually depends on a pistol or noose rather than a logic puzzle, is passed over quickly.

If you have read any of my previous attempts at close textual analysis you might want to try the game yourself. Here are two passages from ‘The Sign of the Four’ which jumped out at me. The first describes Mary Morstan, Holmes’s client and Watson’s love interest, seen from Watson’s perspective:

“She was seated by the open window, dressed in some sort of white diaphanous material, with a little touch of scarlet at the neck and waist. The soft light of a shaded lamp fell upon her as she leaned back in the basket chair, played over her sweet, grave face, and tinting with a dull metallic sparkle the rich coils of her luxuriant hair. One white arm and hand drooped over the side of the chair, and her whole pose and figure spoke of an absorbing melancholy. At the sound of my footfall she sprang to her feet, however, and a bright flush of surprise and of pleasure coloured her pale cheeks.” (182)

The colours are interesting – virginal white, diaphanous like a wedding dress perhaps, but with some touches of scarlet at the neck and waist, suggesting something more carnal? None of these details are accidental, from the observation that she is sitting in a basketchair, (baskets usually being used for possessions) to the fact that her “white arm” is drooping over the side of the chair. Why the whiteness of her arm needs to be emphasised here, given we have already established her ethnicity and dress, is worth asking, and what is suggested by the fact her arm droops rather than rests?

In the second scene I have picked out, Holmes and Watson are watching the boat yard, and while they do so they spot some workmen coming from work: Holmes says

’See how the folk swarm over yonder in the gas-light’
‘They are coming from work in the yard’
‘Dirty looking rascals, but I suppose everyone has some little immortal spark concealed about him. You would not think it, to look at them. There is no a priori about it. A strange enigma is man’” (177). This reverie is interrupted by the signal that the suspects are leaving.

The verb choice “swarm” is telling here, even though describing working men in these terms was not unusual – they are alien, threatening. But Holmes comes close to doubting their humanity. What does this tell us about the portrayal of class in late Victorian literature?