Después del presunto suicidio de su hermano sacerdote, Grace viaja al remoto convento escocés donde cayó y murió. Desconfiando del relato de la Iglesia, descubre un asesinato, un sacrilegio y una inquietante verdad sobre sí misma.
Petty thief Willie Frith steals a suitcase full of bank notes, only to find out that they have been given all the same serial number. But this is only the start of his troubles, now he has to find a way of changing the notes, so he can impress the barmaid of his local pub.
With their headmistress under lock and key in her majesty's prison, the St Trinian's girls find themselves under the protection of the army. However, when the sixth form take a fancy to winning a trip to Italy through means fair or foul, the army discover this is one battle they can't win. Let loose in Europe, it is not long before St Trinian's have succeeded in endangering European relations.