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 arrival of pearls by post from an unknown sender. Driven on by its complexity, Holmes and Watson slowly begin to unravel an intricate web of exotic treasure, secret pacts and mysterious deaths.
