A pre-World War II saber-rattler that finds a munitions inventor kidnapped, a federal agent killed and a beautiful refugee mysteriously missing as Washington's deadly game of espionage and intrigue thunders on...as the FBI hunts the nation's invisble foes! They may have been invisible but their accents and billing names von Morhart, William Vaughn (William von Brincken already hiding under another name before hostilities were formally declared), Frederick Gierman and Walter Bonn---provide clues aplenty as to their country of origin and paymaster.
Charles Farrell
as Barry Scott
June Lang
as Christine Reisner
John Miljan
as Henri Franck
Bernadene Hayes
as Mona Brandt
J. Arthur Young
as Dr. Reisner
David Clarke
as John Brandt
Dave O'Brien
as Ralph Spencer
Charles Sargent
as American Agent
John Dilson
as Harkness
Tom Herbert
as FBI Agent
Ottola Nesmith
as Nazi Wife
Frederick Giermann
as Carl Nash
