We meet Hercule Poirot aboard Le Train Blue, bound for the French Riviera. What begins as an opulent voyage turns macabre when an American heiress is found dead of strangulation in her compartment and a famous ruby, "Heart of Fire" is missing from her belongings. The intrigue deepens as Poirot discovers a web of suspicion involving fellow passengers: Ruth's paramour, the Comte de la Roche; her estranged husband, Derek Kettering; Kettering's spurned Parisian lover, the vengeful Mirelle; and an infamous jewel thief known as "The Marquis." With his legendary charm, élan, and powers of perception, Poirot navigates through the intricate puzzle to expose the elusive culprit who eludes all but Poirot's discerning eye. This Warbler Classics edition includes a biographical note.