The Under Dog - Hercule Poirot, Bk 7 Author:Agatha Christie The "Heart of Fire" is one of those legendary gems that carry through history their grim associations of death and violence. When it comes into the hands of the beautiful American Ruth Kettering, it seems the jewel's mysterious and malignant influence is at work again. Mrs. Kettering is murdered aboard the Blue Train as it crosses France to the ... more »Riviera. Her traveling companion, a quiet English girl, is suddenly thrust into the chilling ritual of crime and detection. Another passenger assumes a much more practiced and professional involvement. As the carriages roll into Nice, Hercule Poirot begins to unravel the Mystery of the Blue Train.« less