Ernst Lubitsch directed Franz Lehar's operetta about a small kingdom that orders their greatest womanizer to marry a very rich widow.
In small Marshovia in 1885 Count Danilo (Maurice Chevalier) marches and sings "Girls, Girls, Girls." He brings his own recommendation to the veiled widow Sonia (Jeanette MacDonald), but she refuses to lift her veil. He leaves, saying it is over. After she sings a lonely song, her maids tell her Danilo's address. Sonia writes in her diary for the first time in almost a year. She gets dressed for Paris. King Achmed (George Barbier) is afraid a foreigner will marry Sonia and take her money out of Marshovia. When he finds his queen (Una Merkel) with Danilo, they pretend to be social and hide the scandal. The king sends Danilo to Paris on a mission.
Danilo sings about Maxime's; while Sonia keeps six suitors waiting, she hears him and goes there. Danilo and Ambassador Popoff (Edward Everett Horton) quarrel, slap each other, realize who each is, laugh, and hug. Popoff tells Danilo that Sonia owns 52% of Marshovia, and he must marry her. Many women greet Danilo enthusiastically, and he dances with them. Sonia tells Danilo she is Fifi. She flirts with him and other men. He gets her into a private room by taking her shoe. Danilo kisses her; they argue over Napoleon, then dance, and kiss again passionately. Fifi tells him he does not know what love is and calls in the girls of "tonight" who don't care about tomorrow.
At the embassy ball Sonia sings and dances. Popoff tells Danilo to get to the embassy, and girls put his uniform on him. Popoff makes Danilo drink coffee and face the widow, although he loves Fifi. Danilo tells Sonia he is in love with Fifi, and they waltz. Popoff gets a telegram from the king that they must marry tonight, and so he announces their wedding. Danilo complains to him. Sonia tells Danilo she knows why he loves her. Danilo announces Sonia was never engaged to him, and he tells Sonia he loves her. She walks out, and he is arrested and taken to Marshovia for trial.
Danilo is accused of treason. Sonia testifies he is innocent, because he served Marshovia as ordered, betraying her. He says he is guilty of being a fool for dancing with many and walking away from one. Sonia visits Danilo in jail. The king and Popoff won't let her out of his cell, provide champagne, perfume, music, and wedding rings. Danilo is willing to walk through life with one woman and get married.
This musical fantasy has an extraordinary lover fall in love with a beautiful and rich widow in elegant waltz time, offering great entertainment stylishly done.