Meisterdetektiv Hercule Poirot (Peter Ustinov) unterhält sich mit dem Broadway-Produzenten Odell Gardener (James Mason, r.). Er scheint als einziger von den Hotelgästen kein Alibi für den Zeitpunkt zu haben, an dem Arlena Marshall ermordet wurde.
Mrs. Oliver, célèbre écrivaine de romans policiers, invite Poirot à participer à une course à l'assassin. Celle-ci se déroule dans le domaine de Georges Stubbs. Mais les événements ne se déroulent pas comme prévu. La fausse victime en devient une vraie, et Hattie, la femme de Sir Georges, vient à disparaître... Hercule Poirot, déjà sur place, ne peut tenter de résister à percer ce secret plein de mystère. Et, comme à chacune de ses enquêtes, il est secondé par son ami le capitaine Hastings.
Après un échec cuisant qui s'est soldé par la mort d'une jeune fille, Poirot est bien décidé à ne plus prendre de nouvelle affaire, sombrant peu à peu dans la dépression. Sur le conseil de son médecin, il se remet en selle avec une nouvelle enquête qui l'emmène à l'Hôtel Olympus, dans les Alpes suisses. Sur place, il rencontre une amie de longue date, ainsi qu'un vieil ennemi. Mais une série de mystères ne tardent pas à se succéder.
A revolution overthrows Prince Ali Yusuf in the Arabian country of Ramat. But before he dies, his friend manages to hide priceless jewels in the tennis racquet of Jennifer Sutcliffe, an English schoolgirl. When term begins at Meadowbank school, everyone notices the new pupil, Princess Shaista, Prince Ali Yusuf's cousin and intended bride. By rights, the jewels now belong to her but nobody knows where they are! Jennifer complains that her tennis racquet is un-useable, and swaps with her friend Julia Upjohn. Hardly a week has passed before the sadistic and unpopular games teacher, Miss Springer is found murdered in the gymnasium. Fortunately, Poirot is an old friend of the Headmistress Miss Bulstrode, and is at the school to help advise her who to choose as a successor when she retires. He is soon making progress, discovering that not everyone is quite who they say they are... First of all, he discovers that the gardener, Adam Goodman, is in fact a Secret Service Spy charged with keeping
A revolution overthrows Prince Ali Yusuf in the Arabian country of Ramat. But before he dies, his friend manages to hide priceless jewels in the tennis racquet of Jennifer Sutcliffe, an English schoolgirl. When term begins at Meadowbank school, everyone notices the new pupil, Princess Shaista, Prince Ali Yusuf's cousin and intended bride. By rights, the jewels now belong to her but nobody knows where they are! Jennifer complains that her tennis racquet is un-useable, and swaps with her friend Julia Upjohn. Hardly a week has passed before the sadistic and unpopular games teacher, Miss Springer is found murdered in the gymnasium. Fortunately, Poirot is an old friend of the Headmistress Miss Bulstrode, and is at the school to help advise her who to choose as a successor when she retires. He is soon making progress, discovering that not everyone is quite who they say they are... First of all, he discovers that the gardener, Adam Goodman, is in fact a Secret Service Spy charged with keeping