Holmes recalls how in his student days, during the long summer vacation, he went to stay on the Norfolk Broads at the grand house of Victor Trevor, his only friend at university (probably Oxford or Cambridge, but this is a point of debate). Over a glass of port one evening, young Victor’s father, Victor Trevor senior, asked Holmes to demonstrate his deductive powers, which his son had been extolling. “Come, now, Mr. Holmes,” he said, “I’m an excellent subject, if you can deduce anything from me.”

Trevor senior, a justice of the peace with a reputation for leniency, was taken aback by Holmes’s perception that in recent months he had been going about in fear of attack. Holmes’s remarkable insight was based on a shrewd observation of Trevor’s walking stick: he could tell from the inscription that the stick was less than a year old, and further noted that it had been hollowed out at the top and filled with lead—presumably in order to be used as a weapon.

Holmes also observed from his host’s flattened and thickened ears that he was once a boxer (a shared enthusiasm), while his callused hands suggested digging. Trevor senior explained that he had made his fortune prospecting for gold.

Holmes, who had earlier observed a semi-erased tattoo on the man’s arm, then added, “And you have been most intimately associated with someone whose initials were J.A., and whom you afterwards were eager to entirely forget.” At this, to both Holmes’s and Trevor junior’s astonishment, Trevor senior slowly stood, stared wildly at Holmes, then fainted. When he came to, Trevor senior declared in admiration of Holmes’s astute, albeit unofficial, detective work, “That’s your line of life, sir, and you may take the word of a man who has seen something of the world.” And that, describes Holmes to the listening Watson, was the moment he realized that he might make a profession out of detective work.

Once recovered, Trevor senior claimed, rather unconvincingly, that “J.A.” was an old flame. Yet afterward he was so uneasy that Holmes resolved to leave. However, the day before his departure, an uninvited guest arrived—an “acid-faced” old sailor named Hudson. Trevor senior clearly knew the sinister-looking man, and poured himself a large brandy. “Why, it’s thirty year and more since I saw you last,” said Hudson. “Here you are in your house, and me still picking my salt meat out of the harness cask.” When he mentioned a mutual acquaintance called Beddoes, Trevor senior, clearly in shock, drank himself into a stupor.

Tea clippers like the Gloria Scott were built for speed, and designed to carry light loads. The only surviving intact example is the Cutty Sark, now moored in Greenwich, London.

Seven weeks later, back in London, Holmes received a telegram from Trevor junior imploring him to return to Norfolk, where his father had suffered a massive stroke. But by the time Holmes reached Trevor’s hamlet, the old man was dead. It transpired that, since Holmes’s last visit, Hudson had exerted a strange hold over Trevor senior and for weeks had terrorized the household. Things came to a head when an argument broke out between Hudson and Trevor junior. Young Victor had then refused to apologize, at which Hudson left for Beddoes’ Hampshire estate. And it was a brief, cryptic message from there, received the day before Holmes’s return to the house, that had brought on the stroke.

The budding detective took some time to decipher the strange message. He read it backward, then tried alternate words, before realizing the key lay in every third word, starting with the first: “The game is up. Hudson has told all. Fly for your life.” No wonder Trevor senior was so affected. But why the bizarre “Head-keeper” and “hen pheasants,” and what secret was Hudson harboring? The odd choice of filler words seemed to validate the message’s authenticity, confirming that Beddoes, an avid hunter, wrote it. But Hudson’s role remained unexplained.

Beddoes warns Trevor senior by way of a cryptic code. The full coded message is shown here, but Holmes deduces that taking every third word (in bold) reveals its true meaning. The use of coded messages for secret communications was common in Victorian Britain.

As Trevor senior gasped his last breath, he told his doctor where to find a letter he had written for his son in the event of his death. The letter revealed that his real name was James Armitage—“J.A.”—and explained how, as a young man working in a London bank, he had stolen money in order to pay a debt, intending to return it before anyone noticed. However, he had been caught, tried, and sentenced to transportation aboard the Gloria Scott, bound for Australia.

Here the plot thickened. It was October 1855, and transportation ships had been enlisted for military uses because of the Crimean War (1853–1856). The ship carrying Armitage was, in fact, a repurposed tea clipper, a lightweight vessel over loaded with almost a hundred crew, prisoners, and soldiers.

At sea, an inmate named Jack Prendergast let Armitage in on an elaborate escape plot. It was already well prepared and financed, and Prendergast’s partner was busy masquerading as the ship’s own chaplain, and secretly bribing the crew and bringing weaponry into the 38 inmates’ cells. They seemed so certain to overwhelm the 18 soldiers and a mere few others that Armitage decided to join in.

The murder of the ship’s captain, illustrated here by Paget in The Strand Magazine, is part of the violent and bloodthirsty mutiny that led Armitage and Evans to flee the ship.

The violence of the mutiny that took place is described in full, gory detail. Conan Doyle, who twice served as a ship’s surgeon—in the Arctic on the whaler Hope in 1880, and off the West African coast on the steamer Mayumba in 1881—has Prendergast ruthlessly cut the throat of the bound and gagged convict ship’s surgeon. Interestingly, however, there is a curious difference between the original British and American descriptions of the murdered ship’s captain. In the British edition, he “lay with his head on the chart of the Atlantic,” whereas the American edition described “his brains smeared over the chart of the Atlantic.” The jury is still out as to which of these was Conan Doyle’s original.

Uneasy with all the wanton bloodletting, several men, including Armitage and another friend named Evans, wanted no more part in it. They escaped in a lifeboat, but as they rowed away the Gloria Scott exploded and they turned back to search for survivors. There was only one amid the wreckage: Hudson. It transpired that a bullet had ignited the ship’s gunpowder.

The men were picked up off Cape Verde by a brig heading for Australia, and managed to convince their rescuers they were from a foundered passenger ship. Once in Australia, Armitage and Evans created new identities, renaming themselves Trevor and Beddoes, respectively, and both made their fortunes. Returning later to England, with their pasts safely buried, it was clear why the return of Hudson, with his knowledge of their part in the mutiny, was so disconcerting.

In concluding his reminiscence, Holmes tells how Victor junior—heartbroken about his father’s disreputable past—became a tea planter in India. And it turned out that Beddoes’ warning that Hudson had “told all” had been wrong. Both Beddoes and Hudson vanished, but although the police thought Hudson had killed Beddoes, Holmes himself suspected the opposite, and that Beddoes had fled the country.

Apart from this surmise, Holmes does little more in this case than decode the cryptic message and read a confessional letter: indeed, the whole case is largely a frame for a pirate story (Conan Doyle was enthusiastic about the genre, and in 1922 wrote a collection called Tales of Pirates and Blue Water).

“The Gloria Scott” may have been inspired by a real-life case of mutiny, aboard the convict ship Cyprus in 1829, in which some convicts refused to take part. Two rowed away—and the captain who picked them up was named Hudson.