Alan Darrel, an energetic young American, visits the little kingdom of Etruria, where he is fortunate enough to save the Princess Griselda from injury in a runaway. Prince Otto, who reigns in the neighboring kingdom of Vosmark, seeks the heart and hand of Princess Griselda. When the Princess refuses him her heart, the Prince vows to go to war. Alan Darrel overhears the plot, visits King Frederick and proposes to encase all the automobile trucks in steel and invent other engines of destruction in order to successfully combat the larger army of Prince Otto. Alan Darrel, the American, slays Prince Otto in an exciting sword combat. He thus wins the love of Princess Griselda.
—Moving Picture World synopsis