 On arrival at Fort Chase, ex-soldier Peter Stirling, recalled to active duty, is re-united with his old pal Francis the Talking Mule. Gradually, it dawns on Peter that a clerical error has assigned him to an all-female WAC base, where broad slapstick is the order of the day and Francis has more horse sense than any of the human officers. Too innocent to appreciate the pleasant aspects of his predicament, Peter ends by helping the "enemy" in a war-game battle of the sexes.