While traveling incognito through his kingdom, Prince Ludwig of Saxe-Tholberg becomes infatuated with Katrina, the daughter of innkeeper Hermann Ardelheim, but their idyll is interrupted by the arrival of a courier bearing the news that Austrania has threatened war. Katrina is heartbroken to discover the identity of her sweetheart whom she can never hope to marry. After Ludwig's departure, Katrina overhears the plotting of two spies and with the help... see more