The narrative centers on a fierce battle of wills between the Marquis—a defiant writer who refuses to be silenced—and the authoritarian Dr. Royer-Collard (Michael Caine), who seeks to suppress his scandalous manuscripts.

: Abbé de Coulmier (Joaquin Phoenix), the asylum's young director, finds himself torn between his religious duties and his sympathy for the Marquis' creative spirit.

: With the aid of a courageous laundress, Madeleine (Kate Winslet), de Sade's erotic works are smuggled out for publication, inciting the wrath of Emperor Napoleon.