In a girls' school known for its chaos and rebellion, the new school year begins with an unexpected twist. The headmistress, the feared and eccentric Miss Fritton, faces the daunting task of keeping a group of students, who seem to live in a constant state of uproar, in line. After learning that the government is about to shut down the school due to its bad reputation, she decides it’s time to prove that they still have something to offer.
With the fiery spirit of freedom and a pinch of madness, the students band together to save their beloved boarding school. Along the way, they become entangled in a series of misadventures, from failed attempts at organizing events to dabbling in the criminal underworld. In a blend of comedy and adventure, the girls encounter a wide array of hilarious characters: from cunning thieves to extremely serious teachers, all while executing their secret plan to raise funds.
The chaos escalates even further when an unexpected attack threatens to derail all their plans. But as they know best, the girls of St. Trinian's fight back with ingenuity and courage, challenging stereotypes and demonstrating that, despite adversity, they have the heart and spirit needed to triumph. The climax is an explosion of joy and madness that leaves everyone wondering what exactly makes this institution so unparalleled.