During World War I, young Dorothy Grant comes home from finishing school and informs her parents that she is going to contribute to the war effort by organizing a "Girls Aviation Corps". She has uniforms made and hires a veteran of the Spanish-American War to teach her "cadets" military routines and drills. Her father owns a munitions factory and is always telling her to be on the lookout for spies. She convinces herself that the family butler, Williams, is a spy because he cuts his grapefruit in an odd way. It turns out that Williams isn't a spy but the people whom Dorothy least suspects are in fact spies, and they discover that Dorothy knows the password to get into the factory after hours.

Graustark needs thirty million dollars to satisfy a Russian loan. The Prince of Dawsbergen, ruler of the adjoining principality, will advance the money if the young Prince of Graustark marries his daughter. Prince Robin, however, inherits an independent spirit, his father having been an American. He refuses absolutely to marry a Princess whom he has never seen. His councilors plead in vain. With the ruin of his country imminent, the boy ruler hastily sails for America to negotiate the loan, hoping at the same time to meet the girl of his dreams. The money is readily advanced by William W. Blithers, a self-made millionaire anxious to have his daughter marry into royalty. The daughter, however, avoids the Prince and he does not see her. He rescues a girl from drowning and falls in love with her. He believes her to be Blithers' daughter, but she does not reveal her identity.

Basil Breckenridge, a broken old man on the verge of starvation, but concealing it because of his proud southern ancestry, is set upon by young ruffians on the street. The old man becomes infuriated and gives the young leader a shaking. His father, Ald. Connors, the city's political boss, happens along and attacks the old man, who strikes at him with his cane. The sword blade inside falls out and the police arrest him on the charge of assault with intent to kill.