Holmes (Basil Rathbone) and Watson (Nigel Bruce) are supposed to be going on holiday but they are tasked with protecting the heir to a European throne. Ruthless agents of a foreign power want to stop (and kill) the heir. Holmes arranges a complicated plot of red herrings and diversions, even Watson is kept in the dark (though the Watson in this series is generally an amiable and loyal buffoon).
Holmes and Watson end up on a cruise ship bound for Algiers. The brutal gang include a circus knife thrower and a deaf mute man mountain and there are also some mysterious archaeologists. The ship's passenger list also includes singer Sheila (Marjorie Riordan) who performs a couple of songs. As does Watson!
Another enjoyable entry in the Rathbone-Bruce series of Sherlock Holmes set in the present day (well 1940s anyway). A crime-spy romp on a cruise ship with Sherlock Holmes, what more can you really want?!