Mona and Carl Johan are having a hard time. They are going to get married, but then Carl Johan is called up to report to the barracks on the wedding night. Carl Johan doesn't want to and goes to the barracks to tell them about it. Mona wants to meet Carl Johan and also leaves, just as Carl Johan is leaving the barracks again. Mona accidentally becomes a hussar and then the riding master's attendant. It is not easy being a woman in the army. After a series of complications, the truth comes out.