Maria and Karl Lang are the singing duo of Vienna. Maria is very flirtatious and Karl very jealous. Karl decides to masquerade as a Russian guardsman and attempts to make Maria flirt with him - to test her loyalty to him - as the Russian, Karl makes a vigorous attempt to seduce Maria. For a moment she accepts then rejects. Karl is left in turmoil...
Nelson Eddy
as Karl Lang
Risë Stevens
as Maria Lanyi
Nigel Bruce
as Bernard Fischer
Florence Bates
as Madame Helene
Dorothy Raye
as Magda
Paul Godkin
as Performer in Gypsy Cafe Sequence
Nydia Westman
as Liesel - Maid
Max Barwyn
as Anton
Charles Judels
as Klementov
Louis Adlon
as
Jimmy Alexander
as Singer - 'Seek the Spy' Sequence
Sig Arno
as Emile, Voice Coach
