A secret shared by four convicts and two prison guards, a daughter in search of her missing father, a strange gift of a single pearl received every year, a fabulous treasure buried in the ancient Agra Fort in India, an eccentric detective being consulted to solve a deadly puzzle. All these events are set against the turbulent backdrop of the Great Indian Mutiny of 1857 in the second Sherlock Holmes novel by Sir Arthur Conan Doyle, The Sign of the Four. Mary Morstan, a lovely young woman, comes to the Baker Street lodgings shared by Holmes and Dr Watson. Her mother died when she was very...