Originally published as a series of short stories in Sketch magazine, this tale of international intrigue and espionage begins when a visitor stumbles into detective Hercule Poirot's bedroom. In the final moments before his death, he tells Poirot of the crime cartel known only as the Big Four. What follows is Hercule Poirot's biggest case yet, taking him and his sidekick Arthur Hastings on the trail of the Big Four before their plans to take control of the world unfold. Note: The Big Four contains characterization and thematic elements representative of prejudiced beliefs, particularly Sinophobia and Orientalism. While these views were never legitimate nor equitable, they were unfortunately commonplace at the time of writing and publication. Rather than glossing over this painful dimension of literary history, this audiobook edition references the text as it was originally published so that it may be included when taking into consideration the overall impact of Agatha Christie's body of work. The beliefs and views present in this book do not reflect that of the publisher's.