HarperCollins is proud to present its incredible range of best-loved, essential classics. ‘How often have I said to you that when you have eliminated the impossible whatever remains, however improbable, must be the truth?’In London, 1888, the razor-sharp detective skills of Sherlock Holmes are to be put to the test. Mary Morstan reports two seemingly unconnected and inexplicable events: the disappearance of her father, a British Indian Army captain, and the annual arrival of pearls from an unknown sender. Driven on by the complexities of their newest case, Holmes and Watson begin to unravel an intricate web of exotic treasure, secret pacts and mysterious deaths.First published in 1890, The Sign of the Four follows the most iconic detective duo in English literature who have continued to delight and entertain readers from its time of publication until today.