Wealthy widow Gloria Teasdale forces the government of Freedonia to accept Rufus T. Firefly as its leader. Firefly's outrageous public behavior offends Ambassador Trentino of Sylvania, who with the help of his confederate, dancer Vera Marcal, intends to take control of Freedonia by marrying Mrs. Teasdale. Firefly, who also makes occasional love to Mrs. Teasdale after learning of her fortune, has in his employ two of Trentino's spies, Chicolini and Pinky, whose battles with a street vendor of lemonade are more effective than their espionage. Firefly's secretary, Bob Roland, decides that Firefly must insult Trentino so that the latter may be deported, and Firefly handles the job with enthusiasm, bringing the two countries to the brink of war. Chicolini and Pinky attempt to steal Freedonia's war plans by impersonating Firefly, and though Firefly is temporarily persuaded that Pinky is his own reflection in a mirror, the job results in Chicolini's capture and trial for treason. Several efforts by Mrs. Teasdale, Trentino and Marcal to effect a reconciliation between Firefly and Trentino only result in Firefly repeating his offensive behavior, and war is finally declared. Chicolini begins the war on the side of Sylvania but soon joins Pinky on Freedonia's side, and Freedonia's soldiers under Firefly's unorthodox command, eventually capture Trentino and emerge victorious.