Louis Mazzini's mother belongs to the aristocratic family D'Ascoyne, but she ran away with an opera singer. Therefore, she and Louis were rejected by the D'Ascoynes. Once adult, Louis decides to avenges his mother and him, by becoming the next Duke of the family. Murdering every potential successor is clearly the safest way to achieve his goal.
Larry Gordon, well-known crime writer, is on a train journey when a scream is heard. Upon investigation, the guard had been mugged and a man murdered. Another man is arrested but the full story is yet to be discovered.