Sign of the Four is one of the outstanding novels of the Sherlock Holmes series. It is a brilliant mixture of suspense and action with the protagonist disentangling an apparently unsolvable mystery and catching the criminal with great panache....

A collection of facsimiles of Dr. Watson's private papers, including notes, telegrams, maps, photographs, newspaper clippings, and other clues to assist the reader in solving the mystery of the Sign of four.

Sherlock Holmes took his bottle from the corner of the mantel-piece and his hypodermic syringe from its neat morocco case. With his long, white, nervous fingers he adjusted the delicate needle, and rolled back his left shirt-cuff. For some little time his eyes rested thoughtfully upon the sinewy forearm and wrist all dotted and scarred with innumerable puncture-marks. Finally he thrust the sharp point home, pressed down the tiny piston, and sank back into the velvet-lined arm-chair with a long sigh of satisfaction.Three times a day for many months I had witnessed this performance, but custom had not reconciled my mind to it. On the contrary, from day to day I had become more irritable at the sight, and my conscience swelled nightly within me at the thought that I had lacked the courage to protest. Again and again I had registered a vow that I should deliver my soul upon the subject, but there was that in the cool, nonchalant air of my companion which made him the last man with whom one would care to take anything approaching to a liberty. His great powers, his masterly manner, and the experience which I had had of his many extraordinary qualities, all made me diffident and backward in crossing him.

The Penguin English Library edition A dense yellow miasma swirls in the streets of London as Sherlock Holmes and Dr Watson accompany a beautiful young woman to a sinister assignation. For Mary Marston has received several large pearls - one a year for the last six years - and now a mystery letter telling her she is a wronged woman. If she would seek justice she is to meet her unknown benefactor, bringing with her two companions. But unbeknownst to them all, others stalk London's fog-enshrouded streets: a one-legged ruffian with revenge on his mind - and his companion, who places no value on human life . . .

The Sign of the Four (1890), also called The Sign of Four, is the second novel featuring Sherlock Holmes written by Sir Arthur Conan Doyle. Doyle wrote four novels and 56 short stories featuring the fictional detective.The story is set in 1888.The Sign of the Four has a complex plot involving service in India, the Indian Rebellion of 1857, a stolen treasure, and a secret pact among four convicts ("the Four" of the title) and two corrupt prison guards. It presents the detective's drug habit and humanizes him in a way that had not been done in the preceding novel, A Study in Scarlet (1887). It also introduces Doctor Watson's future wife, Mary Morstan.According to Mary, in December 1878, her father had telegraphed her upon his safe return from India and requested her to meet him at the Langham Hotel in London. When Mary arrived at the hotel, she was told her father had gone out the previous night and not returned. Despite all efforts, no trace was ever found of him. Mary contacted her father's only friend who was in the same regiment and had since retired to England, one Major John Sholto, but he denied knowing her father had returned. The second puzzle is that she has received six pearls in the mail from an anonymous benefactor, one per year since 1882 after answering an anonymous newspaper query inquiring for her. With the last pearl she received a letter remarking that she has been wronged and asking for a meeting. Holmes takes the case and soon discovers that Major Sholto had died in 1882 and that within a short span of time Mary began to receive the pearls, implying a connection. The only clue Mary can give Holmes is a map of a fortress found in her father's desk with the names of Jonathan Small, Mahomet Singh, Abdullah Khan and Dost Akbar.

The Sign of the Four (1890), also called The Sign of Four, is the second novel featuring Sherlock Holmes written by Sir Arthur Conan Doyle. Doyle wrote four novels and 56 stories starring the fictional detective. The story is set in 1888. The Sign of the Four has a complex plot involving service in East India Company, India, the Indian Rebellion of 1857, a stolen treasure, and a secret pact among four convicts ("the Four" of the title) and two corrupt prison guards. It presents the detective's drug habit and humanizes him in a way that had not been done in the preceding novel, A Study in Scarlet (1887). It also introduces Doctor Watson's future wife, Mary Morstan. Sir Arthur Conan Doyle described how he was commissioned to write the story over a dinner with Joseph M. Stoddart, managing editor of an American publication Lippincott's Monthly Magazine, at the Langham Hotel in London on 30 August 1889. Stoddart wanted to produce an English version of Lippincott’s with a British editor and British contributors. The dinner was also attended by Oscar Wilde, who eventually contributed The Picture of Dorian Gray to the July 1890 issue. Doyle discussed what he called this "golden evening" in his 1924 autobiography Memories and Adventures. The novel first appeared in the February 1890 edition of Lippincott's Monthly Magazine as The Sign of the Four; or The Problem of the Sholtos (five-word title), appearing in both London and Philadelphia. The British edition of the magazine originally sold for a shilling, and the American for 25 cents. Surviving copies are now worth several thousand dollars. Over the following few months in the same year, the novel was then republished in several regional British journals. These re-serialisations gave the title as The Sign of Four. The novel was published in book form in October 1890 by Spencer Blackett, again using the title The Sign of Four. This edition was illustrated by Charles H. M. Kerr. The title of both the British and American editions of this first book edition omitted the second "the" of the original title. Different editions over the years have varied between the two forms of the title, with most editions favouring the four-word form. The actual text in the novel nearly always uses "the Sign of the Four" (the five-word form) to describe the symbol in the story, although the four-word form is used twice by Jonathan Small in his narrative at the end of the story. As with the first story, A Study in Scarlet, produced two years previously, The Sign of the Four was not particularly successful to start with. It was the short stories, published from 1891 onwards in Strand Magazine, that made household names of Sherlock Holmes and his creator. reference : Wikipedia, The Sign of the Four