The Silent Master plot
Valentin Marquis de Sombreiul, alias Monsieur Simon, is known as the Grand Master because he is the leader of a group of Parisian Apaches who apply their own private law to individuals who have violated their code in a secret tribunal known as the Court of St. Simon. In an attempt to cure Eugene, a young American craving excitement, Valentin allows the young man to witness these horrors, causing the young man to be dragged into the Apache gang and receive a prison sentence for one of their crimes. Later, after the Master has disbanded his secret society and married Virginia Arlen, a girl from an aristocratic family, he discovers to his horror that the boy whose life he has ruined is his wife's brother.