Mary Barrett is an aspiring opera singer who is taken under the wings of a famous operatic maestro, Guilio Monterverdi. After spending endless working hours together and arguing, their relationship develops into love. But, jealousy and misunderstandings prevent Mary and Guilio from acknowledging their true feelings.

Bill Roberts is an American radio commentator station in Berlin in the months before Pearl Harbor. Having witnessed Nazi brutalities first hand, Roberts hopes to alert his listeners of impending dangers, and does so by sending out coded messages during his broadcasts. The Gestapo begins to suspect something and assigns glamorous secret agent Karen Hauen to spy on Roberts. When she discovers that her own father is supplying Roberts with vital secrets, she turns her back on the Nazis and joins our hero in his efforts.

A radio correspondent tries to rescue a burlesque queen from her marriage to a Nazi official.

During the Nazi occupation of Poland, an acting troupe becomes embroiled in a Polish soldier's efforts to track down a German spy.

The Invisible Man's grandson uses his secret formula to spy on Nazi Germany.

Pepe Le Moko leads a gang of jewel thieves in the Casbah of Algiers, where he has exiled himself to escape imprisonment in his native France.

A true story based on the popular novel by the Baroness Von Trapp of Austria. The film was made in 1956, some years before the other film based on the Trapp Family's life was released - a little movie named "The Sound of Music".

In 1942, a young paratrooper in the RAF returns to Czechoslovakia to encourage his fellow countrymen to sabotage the German war effort.

Some dastardly criminals have stolen some top secret plans and tattoo them on the back of a woman so she can sell them to the highest bidder in Lisbon. This woman plans to take the place of a 'Sidney Royce', a legitimate traveler going to Lisbon as a reporter. Crossed signals allows the real Sidney to reach Portugal first, where she is pursued by those trying to obtain the plans and US government agents trying to prevent the sale.

Edited version of the 1942 Republic serial "Spy Smasher," cut down to one hour and sold for TV release in 1966 in a syndication package with other truncated Republic serials.