Paris, 1899. President Félix Faure has just died in the arms of his mistress, Marguerite Steinheil (Meg). With the Republic on the verge of explosion, Prefect Lépine is called back to business.
Inspector Jouin is in love with Jeanne, a young lawyer with a strong character, who cannot practice but works with Maître Weidmann in the Jewish quarter. She decides to help him with the Berger case.
The police are working hard to solve the Berger case. A few days before the opening of the Dreyfus trial, tension is mounting in the streets of Paris. Lépine foils to his advantage the trap of personal scandal set for his wife.
Exhausted by years of enslavement and sickened by the Berger affair, Fiersi distances himself from Puybaraud. It provides Jouin with an essential element in his investigation. As for, Jules Guérin, he has taken refuge in rue Chabrol.
While Maman Guérin organises the final details of the riots that are planned on rue Chabrol, Prefect Lépine receives unexpected help from the anarchists.
Jouin wants to find out the whole truth about the Sabran, taking the risk of losing Jeanne. Meg is now thinking about the future and playing her last card with the Prefect.