During the stagecoach trip of a frightened group of inhabitants of Rouen, Elisabeth Rousset, known as "Boule de Suif", renders these people a signal service, but comes up against their stupidity and their sufficiency. A little later, Boule de Suif assassinates the formidable Prussian lieutenant whom his friends had nicknamed Fifi and who shamelessly displayed his taste for pillage and his sadistic tendencies.