This is book number 1928 in the Hercule Poirot Mysteries (Audio) series.
When the luxurious Blue Train arrives at Nice, aguard attempts to wake serene Ruth Kettering fromher slumbers. But she will never wake again--for aheavy blow has killed her, disfiguring her featuresalmost beyond recognition. What is more, herprecious rubies are missing.
The prime suspect is Ruth's estranged husband, Derek. Yet Hercule Poirot is not convinced, so hestages an eerie reenactment of the journey, completewith the murderer on board. . . .