Poirot investigates the murder of an American heiress on the Blue Train. A young heiress is set to inherit her husband's considerable fortune until his family investigates further. Cora Abernathy calls on Poirot to investigate her brother's death, but his work is interrupted when Cora herself is murdered. Mr. Shaitana, a wealthy but mysterious Londoner, invites Poirot and others to an evening of dinner and bridge, but the affair turns deadly when the host is found dead.