After traveling on the Blue Train from Calais to Nice, Hercule Poirot is pressed into service to help solve the murder of heiress Ruth Kettering who is found savagely beaten in her compartment.

Hercule Poirot finds himself investigating the murder of his dinner host, Mr. Shaitana, who was stabbed in the heart while his guests played bridge.

Hercule Poirot's solicitor, Gilbert Entwhistle, asks Poirot to help solve a riddle and a murder.

Hercule Poirot finds himself trying to solve the mystery of the Cloade family