When the Royal family of Ramat are overthrown in a murderous revolution, the heir to the throne, Princess Shaista, is spirited away to the safety of Meadowbanks, an exclusive English girls' school run by the progressive Miss Bulstrode and the ever-faithful Miss Chadwick. But when the bullying games mistress Miss Springer is found dead, impaled on a javelin, it seems Meadowbanks may not be the haven it promised to be and the teaching staff fall under the scrutiny of the world's most formidable detective, Hercule Poirot. Poirot and Inspector Kelsey soon have reason to suspect the unusual collection of staff at the school - timid Miss Rich, iconoclastic Miss Blake and the aloof Mlle Blanch may all have a motive for the murder, and surly new gardener Adam Goodman seems very reluctant to reveal anything of himself. But events take a dramatic twist when school secretary Ann Shapland realises that Princess Shaista is missing and Poirot uncovers the presence of international espionage agents. With another midnight murder and a savage attack on a staff member, Poirot must act quickly to discover the cat among the pigeons before intrepid pupil Julia Upjohn makes a discovery of her own that will place her in mortal danger.