First published in 1928, “The Mystery of the Blue Train” is Agatha’s Christie’s eighth novel. The “Blue Train” is the crack express by which affluent travelers journey from London to the French Riviera. The train trip is necessarily broken by the Channel crossing, but once on French soil there is no need for further change until the arrival at Nice. Somewhere in the course of the train’s journey, Ruth Van Aldin Kettering, the daughter of an American multimillionaire and the wife of an unsatisfactory Englishman whom she is planning to divorce, is murdered in her compartment, strangled with a length of black cord. Police investigations bring to light the presence on the train of various persons involved in the plot, among them the dead woman’s husband and a former suitor of very shady reputation. This briskly paced tale follows the investigation of the murder by Christie’s most famous detective, Hercule Poirot, to its thrilling conclusion. This edition includes a biographical afterword.