Marguerite Gautier, a beautiful Parisian courtesan turned courtesan, falls in love with the son of a country nobleman of modest means. This ardent love makes her give up her former lifestyle and move to the country with the boy. Despite their financial problems, their blissful happiness is interrupted by the appearance of the father, who asks Marguerite to break off her love affair for the sake of the boy. She then returns to Paris and resumes her self-destructive lifestyle, which has a fatal effect on her health. Her lover's heartache only increases when the truth is revealed: she has sacrificed her happiness for his career.

Based on a true story, a love affair develops between a half brother and half-sister. When pregnancy results and word gets out the public is outraged.