El misterio del tren azul

The so-called Blue Train, which travels to Nice, carries a valuable cargo: the world's largest ruby, the "Heart of Fire", a gift from an American oil magnate to his beloved daughter, Ruth Kettering. However, upon reaching the Cote d'Azur, it is discovered that the owner of the jewel has been brutally murdered and that the ruby has disappeared. Ironies of fate, one of the passengers on the train is the great Hercule Poirot, who must put his infallible gray cells to the limit to catch the culprit.