Unpublished cases, also referred to as untold tales or apocryphal cases, are the numerous cases mentioned but not fully detailed in the Sherlock Holmes Short Stories and Novels. They are a common source of inspiration in pastiches and aapatios
The Abergavenny Murder
In "The Adventure of the Priory School", Holmes initially considers himself too busy for an out-of-town client, stating as one of his reasons "'the Abergavenny murder is coming up for trial'".
The Abernetty Family
In "The Adventure of the Six Napoleons", Holmes remarks that '"some of my most classic cases have had the least promising commencement. You will remember, Watson, how the dreadful business of the Abernetty family was first brought to my notice by the depth which the parsley had sunk into the butter upon a hot day.'"
The Addleton Tragedy and the British Barrow
Watson's records for the year 1894 in "The Adventure of the Golden Pince-Nez" include "an account of the Addleton tragedy and the singular contents of the ancient British barrow".
The Aluminium Crutch
In "The Adventure of the Musgrave Ritual", Holmes searches through files of his early cases before his friendship with Watson, noting a record of "the singular affair of the aluminium crutch".
The Amateur Mendicant Society
In "The Five Orange Pips", Watson lists several cases taking place in 1887, including "the Amateur Mendicant Society, who held a luxurious club in the lower vault of a furniture warehouse".
Archie Stamford the Forger
Upon a mention of Farnham, Surrey, in "The Adventure of the Solitary Cyclist", Holmes notes "'you remember, Watson, that it was near there that we took Archie Stamford, the forger'".
The Arnsworth Castle
In "A Scandal in Bohemia", Holmes explains that he has employed the ruse of a house fire to get a woman "to rush to the thing which she values most" one multiple occasions, including "in the Arnsworth Castle business".
The Atkinson Brothers at Trincomalee
As "A Scandal in Bohemia" opens, the recently married Watson has only heard vague accounts of Holmes's doings, among them "his clearing up of the singular tragedy of the Atkinson brothers at Trincomalee".
The Bark Sophy Anderson
Watson's notes from the year 1887 in "The Five Orange Pips" include "the facts connected with the loss of the British bark Sophy Anderson".
In "The Adventure of the Norwood Builder", Holmes schools Watson on the dangers of judging a person by his appearance: "'You remember that terrible murderer, Bert Stevens, who wanted us to get him off in ’87? Was there ever a more mild-mannered, Sunday-school young man?'"
Besmirched by a Blackmailer
In The Hound of the Baskervilles, Holmes initially declines to accompany his client back to Dartmoor because "'at the present instant one of the most revered names in England is being besmirched by a blackmailer, and only I can stop a disastrous scandal'".
The Bishopgate Jewel Case
In The Sign of the Four, police inspector Athelney Jones tells Holmes "'I'll never forget how you lectured us all on causes and inferences and effects in the Bishopgate jewel case. It's true you set us on the right track'".
The Bogus Laundry Affair
In "The Adventure of the Cardboard Box", Inspector Lestrade describes "a big, powerful chap, clean-shaven, and very swarthy" to Holmes as "something like Aldridge, who helped us in the bogus laundry affair".
The Camberwell Poisoning
In "The Five Orange Pips", Watson lists several cases taking place in 1887, including "the Camberwell poisoning case", in which "Holmes was able, by winding up the dead man's watch, to prove that it had been wound up two hours before, and that therefore the deceased had gone to bed within that time—a deduction which was of the greatest importance in clearing up the case".
In "The Adventure of Black Peter", Watson mentions another case from the "memorable year" of 1895: Holmes's "famous investigation of the sudden death of Cardinal Tosca — an inquiry which was carried out by him at the express desire of His Holiness the Pope".
The Coiner's Cuff
Holmes remarks in "The Adventure of Shoscombe Old Place" that "since I ran down that coiner by the zinc and copper filings in the seam of his cuff [Scotland Yard] have begun to realize the importance of the microscope'".
As "The Adventure of Wisteria Lodge" opens, Holmes gripes "'you know how bored I have been since we locked up Colonel Carruthers'".
Colonel Upwood and the Card Scandal of the Nonpareil Club
Following his return to London in The Hound of the Baskervilles, Holmes "exposed the atrocious conduct of Colonel Upwood in connection with the famous card scandal of the Nonpareil Club".
Colonel Warburton's Madness
In the opening line of "The Adventure of the Engineer's Thumb", Watson notes that "of all the problems which have been submitted to my friend, Mr Sherlock Holmes, for solution during the years of our intimacy, there were only two which I was the means of introducing to his notice": the title story and "that of Colonel Warburton's madness".
A Commission from the Sultan of Turkey
Holmes delays the start of his investigation in "The Adventure of the Blanched Soldier" in part because "I had also a commission from the Sultan of Turkey which called for immediate action, as political consequences of the gravest kind might arise from its neglect".
The Conk-Singleton Forgery
Upon wrapping up the mystery in "The Adventure of the Six Napoleons", Holmes asks Watson to "'get out the papers of the Conk-Singleton forgery case'".
While listing his prior connections to Germany in "His Last Bow", Holmes mentions that it was he "'who saved from murder, by the Nihilist Klopman, Count Von und Zu Grafenstein'", the maternal uncle of Von Bork.
The Cutter Alicia
In "The Problem of Thor Bridge", Watson lists some of Holmes's unsolved cases, including "that of the cutter Alicia, which sailed one spring morning into a small patch of mist from where she never again emerged, nor was anything further ever heard of herself and her crew".
The Darlington Substitution Scandal
In "A Scandal in Bohemia", Holmes explains that he has employed the ruse of a house fire to get a woman "to rush to the thing which she values most" one multiple occasions, noting "in the case of the Darlington substitution scandal it was of use to me".
The Disappearance of James Phillimore
In "The Problem of Thor Bridge", Watson lists some of Holmes's unsolved cases, including "that of Mr. James Phillimore, who, stepping back into his own house to get his umbrella, was never more seen in this world".
Dr Moore Agar
In "The Adventure of the Devil's Foot", Watson writes "in March of  Dr Moore Agar, of Harley Street, whose dramatic introduction to Holmes I may some day recount, gave positive injunctions that the famous private agent would lay aside all his cases and surrender himself to complete rest if he wished to avert an absolute breakdown".
The Dundas Separation
In "A Case of Identity", Watson remonstrates against Holmes's claim that real life is "infinitely stranger" than fiction, positing that a newspaper article on an abusive husband will follow a predictable arc of drunkenness, adultery, and shoving. In fact, Holmes replies "'This is the Dundas separation case, and, as it happens, I was engaged in clearing up some small points in connection with it. The husband was a teetotaler, there was no other woman, and the conduct complained of was that he had drifted into the habit of winding up every meal by taking out his false teeth and hurling them at his wife, which, you will allow, is not an action likely to occur to the imagination of the average story-teller.'"
The Dutch Steamship Friesland
Watson writes of a quiet period leading up to "The Adventure of the Norwood Builder" which nevertheless brought Holmes and him "the shocking affair of the Dutch steamship Friesland, which so nearly cost us both our lives".
Early English Charters
As "The Adventure of the Three Students" opens, Holmes and Watson are staying in a university town while Holmes is "pursuing some laborious researches in early English charters—researches which led to results so striking that they may be the subject of one of my future narratives".
The Ferrers Documents
In "The Adventure of the Priory School", Holmes initially considers himself too busy for an out-of-town client, stating as one of his reasons "'I am retained in this case of the Ferrers Documents'".
Francois le Villard
In The Sign of the Four, Holmes tells Watson "'my practice has extended recently to the Continent... I was consulted last week by Francois le Villard, who, as you probably know, has come rather to the front lately in the French detective service... The case was concerned with a will and possessed some features of interest. I was able to refer him to two parallel cases, the one at Riga in 1857, and the other at St. Louis in 1871, which have suggested to him the true solution'".
The French Government
In "The Adventure of the Final Problem", Watson writes that "I saw in the papers that he had been engaged by the French government upon a matter of supreme importance, and I received two notes from Holmes, dated from Narbonne and from Nîmes, from which I gathered that his stay in France was likely to be a long one".
The Giant Rat of Sumatra
In "The Adventure of the Sussex Vampire", Holmes receives a letter from a legal firm that mentions "We have not forgotten your successful action in the case of Matilda Briggs". Holmes expands on this by saying "'Matilda Briggs was not the name of a young woman, Watson... It was a ship which is associated with the giant rat of Sumatra, a story for which the world is not yet prepared'".
The Great Hiatus
Upon his return from three years of presumed death in "The Adventure of the Empty House", Holmes explains that "'I travelled for two years in Tibet.. and amused myself by visiting Lhassa and spending some days with the head Lama. You may have read of the remarkable explorations of a Norwegian named Sigerson, but I am sure that it never occurred to you that you were receiving news of your friend. I then passed through Persia, looked in at Mecca, and paid a short but interesting visit to the Khalifa at Khartoum, the results of which I have communicated to the Foreign Office. Returning to France I spent some months in a research into the coal-tar derivatives, which I conducted in a laboratory at Montpellier'".
The Grice Patersons in the Island of Uffa
In "The Five Orange Pips", Watson lists several cases taking place in 1887, including "the singular adventures of the Grice Patersons in the island of Uffa".
The Grosvenor Square Furniture Van
In "The Adventure of the Noble Bachelor", Holmes mentions "'the little problem of the Grosvenor Square furniture van. That is quite cleared up now—though, indeed, it was obvious from the first.'"
Holmes Refuses a Knighthood
Watson writes that "The Adventure of the Three Garridebs" took place "in the same month that Holmes refused a knighthood for services which may perhaps some day be described".
Huret the Boulevard Assassin
Watson's records for the year 1894 in "The Adventure of the Golden Pince-Nez" include "the tracking and arrest of Huret, the Boulevard assassin—an exploit which won for Holmes an autograph letter of thanks from the French President and the Order of the Legion of Honour".
An Intricate Matter from Marseilles
As "A Case of Identity" opens, Holmes has "some ten or twelve" active cases, "'but none which present any feature of interest... save for one rather intricate matter which has been referred to me from Marseilles'".
In "The Problem of Thor Bridge", Watson lists some of Holmes's unsolved cases, including "that of Isadora Persano, the well-known journalist and duellist, who was found stark staring mad with a match box in front of him which contained a remarkable worm said to be unknown to science".
In "The Adventure of the Greek Interpreter", Mycroft Holmes tells his brother "'By the way, Sherlock, I expected to see you round last week, to consult me over that Manor House case. I thought you might be a little out of your depth'". Sherlock replies that he has solved it, to which Mycroft says "'It was Adams, of course... I was sure of it from the first'"
Following his return to London in The Hound of the Baskervilles, Holmes "defended the unfortunate Mme. Montpensier from the charge of murder which hung over her in connection with the death of her step-daughter, Mlle. Carere, the young lady who, as it will be remembered, was found six months later alive and married in New York".
The Most Winning Woman
Explaining how crucial it is "'not to allow your judgment to be biased by personal qualities'", Holmes notes in The Sign of the Four that "'the most winning woman I ever knew was hanged for poisoning three little children for their insurance-money'".
Mrs Farintosh and the Opal Tiara
In "The Adventure of the Speckled Band", Helen Stoner tells Holmes "'I have heard of you from Mrs Farintosh, whom you helped in the hour of her sore need.'" Holmes recalls the case after consulting a small book, noting "'it was concerned with an opal tiara. I think it was before your time, Watson.'"
The Netherland-Sumatra Company and Baron Maupertuis
As "The Adventure of the Reigate Squire" opens, Holmes's health has not yet "recovered from the strain caused by his immense exertions in the spring of '87. The whole question of the Netherland-Sumatra Company and of the colossal schemes of Baron Maupertuis are too recent in the minds of the public, and are too intimately concerned with politics and finance to be fitting subjects for this series of sketches."
In "The Disappearance of Lady Frances Carfax", Holmes sends Watson to follow the investigation to Switzerland because "'you know that I cannot possibly leave London while old Abrahams is in such mortal terror of his life'".
Old Baron Dowson
Hearing that he was not recognised through a series of disguises in "The Adventure of the Mazarin Stone", Holmes boasts '"Old Baron Dowson said the night before he was hanged that in my case what the law had gained the stage had lost'".
The Old Russian Woman
In "The Adventure of the Musgrave Ritual", Holmes searches through files of his early cases before his friendship with Watson, noting a record of "the adventure of the old Russian woman".
The Paradol Chamber
In "The Five Orange Pips", Watson lists several cases taking place in 1887, including "the adventure of the Paradol Chamber".
The Persecution of John Vincent Harden
Holmes is initially irked by the arrival of his client in "The Adventure of the Solitary Cyclist", as he is "immersed at the moment in a very abstruse and complicated problem concerning the peculiar persecution to which John Vincent Harden, the well-known tobacco millionaire, had been subjected".
The Politician, the Lighthouse, and the Trained Cormorant
Watson writes in "The Adventure of the Veiled Lodger" that there has been pressure to destroy his records of "the social and official scandals of the late Victorian era", to which he makes it known that "I have Mr. Holmes’s authority for saying that the whole story concerning the politician, the lighthouse, and the trained cormorant will be given to the public. There is at least one reader who will understand."
Several visitors mention that they were referred to Holmes by others, implying previous cases without giving much information beyond the client's name. In The Sign of the Four, Mary Morstan consults Holmes "'because you once enabled my employer, Mrs Cecil Forrester, to unravel a little domestic complication'".
In "The Adventure of the Noble Bachelor", the title character states "'Lord Backwater tells me that I may place implicit reliance upon your judgement and discretion.'" In the same tale, Holmes takes the haughty noble down a notch by telling him his last high-class client was "the King of Scandinavia".
In The Hound of the Baskervilles, Holmes is "warmly greeted" by a district messenger office manager, prompting the exchange "'Ah, Wilson, I see you have not forgotten the little case in which I had the good fortune to help you?' 'No, sir, indeed I have not. You saved my good name, and perhaps my life'".
The client in "The Adventure of the Red Circle", a landlady, tells Holmes "'you arranged an affair for a lodger of mine last year... Mr. Fairdale Hobbs'".
In her introductory letter to Holmes in "The Adventure of the Three Gables", the resident of the titular house writes "I believe that my late husband, Mortimer Maberley, was one of your early clients".
Holmes mentions a few criminals he has tangled with without giving much further detail. Of John Clay, the villain in "The Adventure of the Red-Headed League", he says "'we have had some skirmishes, but we had never set eyes upon each other before'". In "The Adventure of the Empty House" he flips past an index entry on "'Mathews, who knocked out my left canine in the waiting-room at Charing Cross'". In "The Adventure of the Missing Three-Quarter" he notes "'Henry Staunton, whom I helped to hang'". In "The Adventure of the Bruce-Partington Plans" he mentions "'Brooks or Woodhouse, or any of the fifty men who have good reason for taking my life'".
The Red Leech and Crosby the Banker
Watson's records for the year 1894 in "The Adventure of the Golden Pince-Nez" include "notes upon the repulsive story of the red leech and the terrible death of Crosby the banker". The punctuation leaves it ambiguous as to whether this comprises one case or two.
The Reigning Family of Holland
As "A Scandal in Bohemia" opens, the recently married Watson has only heard vague accounts of Holmes's doings, among them "the mission which he had accomplished so delicately and successfully for the reigning family of Holland". This is referred to again in "A Case of Identity", when Holmes explains that his expensive new ring "'was from the reigning family of Holland, though the matter in which I served them was of such delicacy that I cannot confide it even to you'".
Ricoletti of the Club-Foot and his Abominable Wife
In "The Adventure of the Musgrave Ritual", Holmes searches through files of his early cases before his friendship with Watson, noting a "a full account of Ricoletti of the club-foot, and his abominable wife".
The Smith-Mortimer Succession
Watson's records for the year 1894 in "The Adventure of the Golden Pince-Nez" include "the famous Smith-Mortimer succession case".
The Tankerville Club Scandal
In "The Five Orange Pips", client John Openshaw states "'I heard from Major Prendergast how you saved him in the Tankerville Club scandal", to which Holmes replies "He was wrongfully accused of cheating at cards'".
In "The Adventure of the Musgrave Ritual", Holmes searches through files of his early cases before his friendship with Watson, noting a "record of the Tarleton murders".
The Tired Captain
Watson describes "The Adventure of the Naval Treaty" as one of three cases of interest taking place in the July following his marriage, naming another as "'The Adventure of the Tired Captain'".
The Trepoff Murder
As "A Scandal in Bohemia" opens, the recently married Watson has only heard vague accounts of Holmes's doings, among them "his summons to Odessa in the case of the Trepoff murder".
The Two Coptic Patriarchs
In "The Adventure of the Retired Colourman", Holmes asks Watson to investigate a fresh crime scene on his behalf because "'I am preoccupied with this case of the two Coptic Patriarchs, which should come to a head to-day'".
Holmes reveals that the spy mission culminating in "His Last Bow" involved two years of international undercover work, saying "'I started my pilgrimage at Chicago, graduated in an Irish secret society at Buffalo, gave serious trouble to the constabulary at Skibbareen, and so eventually caught the eye of a subordinate agent of Von Bork, who recommended me as a likely man... Since then I have been honoured by his confidence, which has not prevented most of his plans going subtly wrong and five of his best agents being in prison. I watched them, Watson, and I picked them as they ripened.'"
"V" Index Cases
In "The Adventure of the Sussex Vampire", Holmes thumbs through the "V" volume of his indexes, noting "'Victor Lynch, the forger. Venomous lizard or gila. Remarkable case, that! Vittoria, the circus belle. Vanderbilt and the Yeggman. Vipers. Vigor, the Hammersmith wonder'". As these form a "record of old cases, mixed with the accumulated information of a lifetime", not all are necessarily his own investigations.
Vamberry the Wine Merchant
In "The Adventure of the Musgrave Ritual", Holmes searches through files of his early cases before his friendship with Watson, noting a record of "the case of Vamberry, the wine merchant".
In The Hound of the Baskervilles, Holmes mentions "'I was exceedingly preoccupied by that little affair of the Vatican cameos, and in my anxiety to oblige the Pope I lost touch with several interesting English cases'".
A Very Commonplace Little Murder
In "The Adventure of the Naval Treaty", Watson finds Holmes engaged in a chemical test. "'If this paper remains blue, all is well. If it turns red, it means a man's life.' He dipped it into the test-tube and it flushed at once into a dull, dirty crimson... 'A very commonplace little murder'".
Wilson the Canary Trainer
In "The Adventure of Black Peter", Watson mentions another case from the "memorable year" of 1895: Holmes's "arrest of Wilson, the notorious canary-trainer, which removed a plague-spot from the East End of London".
The Woman at Margate
In "The Adventure of the Second Stain", Holmes comments on a woman who "manoeuvred to have the light at her back" so they could not read her expression, but concedes of a red herring in his past: "'the woman at Margate whom I suspected for the same reason. No powder on her nose—that proved to be the correct solution.'"