Armand and Marguerite meet first in her home, where she is giving a party for the easy-living Paris ladies and gentlemen. Armand at once falls in love with her, and as Marguerite is taken ill during the dancing, he is the only one who is taking care of her. In the second act the two have grown more familiar, although Marguerite has not quite given up her old acquaintances. One day, for instance, Armand has to leave her for the sake of a count, who has invited her for a drive. From the street Armand has watched the count's visit, and in a fit of passionate jealousy, he writes a letter to Marguerite, saying: "I have seen the count enter your place. You must choose between him and me." Marguerite's friend gives her the letter. One minute later the agreement is made, and the count drives off alone. The lovers now go into the country to live in an unpretending villa, where they are enjoying their happiness as a young married couple. Armand's money does not suffice, and quite secretly ...