The Mystery of the Blue Train by Agatha Christie

"The Mystery of the Blue Train" by Agatha Christie follows the famous detective Hercule Poirot as he investigates a murder aboard the luxurious Blue Train traveling from Calais to Nice. Ruth Kettering, a wealthy American heiress, is found dead, and her valuable ruby necklace is missing. Poirot unravels a complex web of motives and suspects, including shady characters and unexpected connections, in his quest to solve the mystery and unmask the killer. The novel is a classic example of Christie's masterful storytelling and intricate plot twists."