After Roger Laroque maims Louversan, his look-alike, in an honorable duel during the Franco-Prussian War, Louversan swears revenge on his better. In Paris, Roger falls in love with Julia, who he later discovers is married to Lucien, his close army friend. Out of duty to Lucien, Roger ends the affair and leaves for the country where he meets and marries Marie Greville, his uncle's ward. Furious at Roger's desertion, Julia vows revenge and joins forces with Louversan.
