Based on the Romberg-Hammerstein operetta, a fugitive French duke is sold as a bondsman to an aristocrat and becomes a pirate.
In 1789 on a ship from France to New Orleans Marianne de Beaumanoir (Jeanette MacDonald) sings "Strangers in Paris." Charles Duc de Villiers (Nelson Eddy) and prisoners complain they need food. Marianne meets Charles and thinks he is an officer. The Governor (Grant Mitchell) welcomes Marianne. Charles is her servant, and her manager says he bought him for her. She tests Charles' knowledge as a valet. Charles polishes and sings "Shoes." She says he acts like a nobleman. Marianne gives a party and sings "One More Kiss." Valerie de Rossac (Mary Boland) wants to buy Charles from her. Charles learns that the ship New Moon arrived and expects rescue. He and Marianne watch slaves celebrate. They sing "Wanting You" and kiss.
The Governor brings Vicomte Ribaud (George Zucco); they are searching for the Duc de Villiers, who escaped as a bondservant and plans to free others. Marianne tells Charles she sold him to Valerie and sends him off on a horse. Marianne sings "Lover Come Back." Alexander (Dick Purcell) tells Charles that Ribaud commands the New Moon with marines. Charles and others free prisoners, and Charles persuades them to attack the ship. He sings "Stout-hearted Men" as they march. They take the ship and sail away. Marianne sails with Ribaud on a ship with brides for Martinique. Pirates take over their ship, and Charles gives orders. Marianne asks Charles to take her back to New Orleans, but he refuses. In a storm the ship is wrecked on rocks.
On the uncharted island Charles tells Marianne he will treat her well and tells her to cook. Charles stops a fight over a woman. Father Michel (H. B. Warner) foresees trouble. So Charles gives a speech urging them to form families. Several men court Marianne, who complains to Charles. He says he will let her marry him to live in separate rooms. She declines but changes her mind and marries him, giving an ambiguous speech. After the dancing they are carried to Charles' house. He explains the Duc de Villiers' princess was his grandmother. Marianne tells Charles she wants to be friends. He kisses her goodnight, and French ships attack with cannons. Marianne and Charles reprise "Lover Come Back." Charles returns with the French and tells her that France is a republic. Then he carries her into his house.
This romantic musical challenges the social classes
of the 18th century by having a revolutionary Duke serve in bondage
but then become a pirate to show that even outlaws can live as
equals. The French Revolution then provides the happy ending.