Maurice Chevalier plays a 19th century Viennese lieutenant, conducting an affair with sexy violinist Claudette Colbert. While publicly flirting with Colbert, Chevalier is spotted by a dowdy princess (Miriam Hopkins), who thinks that the lieutenant's wink was meant for her. Forced to marry the Princess, Chevalier despairs at her lack of charm. But good-hearted Colbert takes the princess aside, dolls her up, and instructs her how to bewitch--and keep--her man. Chevalier is enchanted by the "new" princess, while Colbert, who will have no trouble finding someone else to keep her warm and comfortable, cheerfully sashays out of his life. Long thought lost, The Smiling Lieutenant was rediscovered in an East European vault in the 1970s.