Marco, a traveling soldier in Renaissance Italy, enters the employ of an ambitious lord named Astolfo whose cruel reign is being challenged by a rebel known as "the Red Mask." Marco soon becomes romantically involved with both Karima, a Gypsy woman, and Iolanda, Astolfo's niece who blames her uncle for her father's death. Intrigues at the court soon result in Marco's fall from favor. He's about to be executed when a rebellion erupts in which the Red Mask's true identity is dramatically revealed.