Sherlock Holmes is thought to have perished in the abyss of the Reichenbach Falls along with his nemisis, Professor James Moriarty. However, he astonishes Dr Watson, his long-time friend, by returning to London three years later. And the timing of his return is most opportune, for London is in the grip of a dangerous murderer. Once more, Sherlock must put his master skills to use and find this crafty criminal. This is a selection of six of Sherlock Holmes' most engaging and baffling mysteries.