Synopsis by Janiss Garza
John Snark (Maurice Costello) has an estate that is about to increase in value because of a railroad being built through town. There is a battle over who will buy the property. Villainous postmaster Henry Murden (Roy Applegate) and the miserly David Creed (Bernard Siegel) both want to get their hands on it. Snark, however, wants to sell it to the father (Herbert Pattee) of his loyal assistant Rose (Alice Joyce), providing it is kept in trust for Rose. Murden vengefully calls on the White Riders (based, apparently, on the Ku Klux Klan) to kidnap Snark. Rose's father is a member of the White Riders, but unwillingly so -- Murden has something on him and therefore controls him. So Rose hears of the plot through her father, dons the white robe of the group, and foils the plot. When Snark is saved, he admits his love for his assistant (as if it wasn't obvious enough already). The Cambric Mask was based on a story by the ever-popular Robert W. Chambers.