Dir: Roy William Neill
Starring: Basil Rathbone and Nigel Bruce
Sherlock Holmes is recruited to escort the heir to a European throne safely back to his homeland after his father’s assassination
This Sherlock Holmes crime film is mostly an original story, though it does feature some characters and events from the 1911 story The Adventure of the Red Circle. It was the twelfth film of the Basil Rathbone / Nigel Bruce series of 14 Sherlock Holmes films and it contains a cropped shot of a steam tank locomotive shunting in a dockyard scene.