![The Big Store](https://image.tmdb.org/t/p/w185/3lY9bR7a0xc8XMyGkvg7S3DkMEZ.jpg)
After the King of Ruthenia has been assassinated, Holmes and Watson are engaged to escort his son to Europe via Algiers, aboard a transatlantic ocean liner which also carries a number of suspicious persons, any of whom may be involved in a plot to also assassinate him.