Hungary's most popular musical comedy team, Karl Lang (Nelson Eddy) and Maria Lanyi (Rise Stevens) are married to the stage as well as to each other. But after six months of wedded bliss, Karl convinces himself that his flirtatious wife is planning to leave him. Deciding to put Maria's loyalty to the test, he woos her in the guise of a Russian guardsman, unaware she's seen through his act and is pretending to fall for his charms just to teach him a lesson.