Sherlock Holmes and the Queen of Diamonds

When Thomas Howard of Missouri had come out of nowhere, one foggy night, and rescued Countess Elaina Montague from rape and robbery, he was apparently in England to find his brother who had disappeared. The Countess offered to enlist Sherlock Holmes to help Howard in his search, though he was already investigating a rash of audacious jewel-thefts. However, the Great Detective, suspecting that there was more to Mr Howard than met the eye, accepted the case. This led to their involvement in a vicious blood feud, a spectacular - death-defying - daylight robbery and a thrilling climax below the brooding River Thames.