The Firefly (1937)

Nina Maria Azara is the beautiful and alluring singing spy for Spain during the Napoleonic Wars Her mission is to seduce French officers in order for them to reveal Napoleons intentions toward Spain She is sent to Bayonne France to gather military secrets Prior to this she meets Don Diego while performing at a club Unknown to her Don Diego is actually Captain Andre who is sent to Spain to spy on her While in France Nina discovers Diegos true identity only after she has fallen in love with him Nina Maria outwits her potential captors returns to Spain and goes into hiding Napoleons troops invade Spain resulting in Ninas capture In a strange twist of fate Nina and Captain Andre are reunited but the 2 nations are now at war