When a wealthy heiress is found murdered aboard the luxurious Blue Train, Hercule Poirot must navigate a web of deceit to uncover the killer. The Belgian detective is tasked with solving the brutal death of Ruth Kettering, whose priceless rubies have vanished alongside her life. Poirot faces a cast of suspicious travelers, each harboring secrets that complicate his investigation into the train's confined environment. The narrative follows a traditional third-person perspective, emphasizing logical deduction and the meticulous observation of human behavior to expose the culprit.

This work is widely recognized as a quintessential example of the Golden Age detective novel, showcasing the author's mastery of the locked-room style mystery. Readers often highlight the atmospheric setting of the Blue Train as a primary draw, noting how the confined space intensifies the interpersonal conflicts among the passengers. While some critics have noted that the plot relies heavily on conventional tropes of the genre, the characterization of Poirot remains a consistent point of praise for his sharp wit and analytical prowess. The novel continues to be studied for its structural precision and its ability to maintain suspense through careful pacing and calculated reveals.