La Conquête de Plassans is a novel by Emile Zola.

The heroine of this book is Marthe Rougon, the youngest daughter of Pierre and Felicite Rougon (from Zola's La Fortune des Rougon), who had inherited much of the neurasthenic nature of her grandmother Adelaide Fouque. She married her cousin, Francois Mouret. Plassans, where the Mourets lived, was becoming a stronghold of the clerical party, when Abbe Faujas, a wily and arrogant priest, was sent to win it back for the Government. This powerful and unscrupulous ecclesiastic ruthlessly set aside every obstacle to his purpose, and in the course of his operations wrecked the home of the Mourets. Marthe having become infatuated with the priest, ruined her family for him and died neglected. Francois Mouret, her husband, who by the machinations of Faujas was confined in an asylum as a lunatic, became insane in fact, and having escaped, brought about a conflagration in which he perished along with the disturber of his domestic peace.