Richard Duvall is a young American detective in the employ of the French Secret Police. While in Paris he meets Grace Ellicot, also an American, with whom he falls in love.
The Devil, in the guise of a human, meets a young couple who remark upon looking at a Renaissance painting of a martyr that Evil could never triumph over Good.
The story of Silvio Pellico who was arrested on the charge of carbonarism and conveyed to the Santa Margherita prison, then moved to the Piombi at Venice The sentence of death pronounced on him in February 1822 was finally commuted to fifteen years of jail in harsh condition, and he was placed in the Spielberg, at Brünn (today's Brno).
Out of the blue, war is declared, making two otherwise friendly neighbouring nations deadly enemies. Amid the inferno, finding themselves on different sides of the conflict, Elsa and Alexis are forced to call off their engagement.
Mabel has just gotten engaged during a housewarming party of which her mother is the hostess. When an annoying party guest persuades Mabel to dance with him, Mabel hurries through the dance and then goes to look for her fiancé, only to discover him caressing another woman.