Catherine Arouette was a resident in an alternate Paris. Her brother was sentenced to death by the fake Marquis de Sade. She wanted revenge on him and his master Minski, and took on the identity of Fantômas, the director of an acting troupe. She had to reveal her true identity to Bressac to dissuade his romantic interests.
She met with Larkspur and Tyll Howlglass to talk about the imminent British invasion. Eging and Garce, agents of the Pageant, found them and killed Larkspur and Howlglass. When Eging tried to shoot Fantômas, Bressac jumped in the way and took the bullet. Driven crazy by the dying screams of Larkspur and Howlglass, Garce shot Eging in the head and ran. Arouette pursued and killed him.
She took the troupe to the New Bastille to perform a play for Minski. When she tried to kill him, she was stopped by her troupe, who had ingested Minski's virus and were under his control. Before they could kill her, the real de Sade appeared and shot Minski, critically injuring him. (PROSE: The Man in the Velvet Mask)