The scene takes place in Paris in March 1793 during the Reign of Terror. The Knight of Maison-Rouge, posing as Citizen Morand, is organizing the escape of Queen Marie-Antoinette. He is assisted in his undertaking by Dixmer, a master tanner who passes himself off as an ardent revolutionary and his wife Geneviève, who also happens to be the Knight's sister. While on mission with her brother, she is saved from arrest thanks to the intervention of Lieutenant Maurice Lindey. Geneviève, who is married without love to Dixmer, falls for the young man, who requites her love. A tunnel is dug between a house rented by Dixmer and the Tower of the Temple but the various attempts to rescue the queen attempts fail. Marie-Antoinette risks the guillotine/ Moreover, Lindey finds himself involved in the plot...

Charming Mimi-Trottin is in love with typographer Louis Chausson, nicknamed Godasse. She meets Doudou, actually a Vicomte, estranged with his parents who are rich automobile manufacturers. Godasse abandons Mimi because of his professional ambitions and Doudou rescues her from a suicide. After making peace with his parents, the young man has Mimi hired as a typist at the factory. After winning a race with one of his father's car, he soon wins the heart and the hand of Mimi.