Thomas Howard of Missouri came out of nowhere, one foggy night, to rescue Countess Elaina Montague from rape and robbery. He was in England, he said, to find his brother, who had disappeared. To repay him, the beautiful Countess offered to enlist her friend, Sherlock Holmes, to help in the search. At the time Holmes was investigating a rash of audacious jewel-thefts, and much to Watson's dismay spending altogether too much time at the music-hall. But because the Great Detective felt that there was more to the mysterious Mr Howard than met the eye, he accepted the case. This in turn led to their involvement in a vicious blood-feud, a spectacular - not to mention death-defying - daylight robbery, the possibility of a serious diplomatic incident and finally, a thrilling climax below the brooding River Thames.