The unruly schoolgirls of St Trinian's are more interested in men and mischief than homework and hockey. But greater trouble than ever beckons when the arrival at the school of Princess Fatima of Makyad coincides with the return of recently expelled Arabella Fritton, who has the kidnap of a prize racehorse on her mind.

A federal agent and a female reporter team up to catch a criminal gang that has kidnapped a scientist in order to get his formula for a new type of poison gas.

An escaped murderer flees France to England, where he forces an ex-forger, now established as a reputable estate owner, and the forger's daughter who knew nothing of his past, to counterfeit 5-pound notes for mass distribution around the countryside.