When it is announced that term is about to begin at St. Trinian's, townspeople board up their shops, and policemen panic, for St. Trinian's is a school like no other. Presided over by headmistress Miss Fritton, the unorthodox free expression she preaches leads to her students being uninhibited. When a Sultan's daughter arrives as a new pupil, her father's prize racehorse is suddenly the centre of attention.