This extraordinary collection puts together eight books:A Study in Scarlet (1887)The Sign of the Four (1890)The Adventures of Sherlock Holmes (1892)The Memoirs of Sherlock Holmes (1894)The Hound of the Baskervilles (1902)The Return of Sherlock Holmes (1904)The Valley of Fear (1914)His Last Bow (1917)BOOK ONEA Study in Scarlet is an 1887.The story marks the first appearance of Sherlock Holmes and Dr. Watson, who would become the most famous detective duo in popular fiction. The book's title derives from a speech given by Holmes, a consulting detective, to his friend and chronicler Watson on the nature of his work, in which he describes the story's murder investigation as his "study in scarlet": "There's the scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it.BOOK TWO:The Sign of the Four 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.BOOK THREE:The Adventures of Sherlock Holmes is a collection of twelve short stories by Arthur Conan Doyle, first published on 14 October 1892. It contains the earliest short stories featuring the consulting detective Sherlock Holmes, which had been published in twelve monthly issues of The Strand Magazine from July 1891 to June 1892. The stories are collected in the same sequence, which is not supported by any fictional chronology. The only characters common to all twelve are Holmes and Dr. Watson and all are related in first-person narrative from Watson's point of view.BOOK FOUR: The Memoirs of Sherlock Holmes is a collection of short stories. The twelve stories were originally published in The Strand Magazine from December 1892 to December 1893 as The Adventures number 13 to 24. For instance, "The Final Problem" was published under the subheading "XXIV.--The Adventure of the Final Problem."[3]BOOK FIVE:The Hound of the Baskervilles is the third of the four crime novels. Originally serialised in The Strand Magazine from August 1901 to April 1902, it is set largely on Dartmoor in Devon in England's West Country and tells the story of an attempted murder inspired by the legend of a fearsome, diabolical hound of supernatural origin. Sherlock Holmes and his companion Dr. Watson investigate the case. This was the first appearance of Holmes since his apparent death in "The Final Problem", and the success of The Hound of the Baskervilles led to the character's eventual revival.BOOK SIX:The Return of Sherlock Holmes is a 1905 collection of 13 Sherlock Holmes stories.The first story is set in 1894 and has Holmes returning in London and explaining the period from 1891-1894, a period called "The Great Hiatus" by Sherlockian enthusiasts. Also of note is Watson's statement in the last story of the cycle that Holmes has retired, and forbids him to publish any more stories.BOOK SEVEN:The Valley of Fear is the fourth and final Sherlock Holmes novel by Sir Arthur Conan Doyle. It is loosely based on the Molly Maguires and Pinkerton agent James McParland.BOOK EIGHTHis Last Bow: Some Reminiscences of Sherlock Holmes is a 1917 collection of previously published. Holmes is long retired from his profession of detective but is still alive and well, albeit suffering from a touch of rheumatism.