"Five men occupied their usual places in a first-class carriage, but the sixth place was empty..." It is most unusual for the sixth man, Mr. Parador, to be late. The five commuters are wondering what happened to him, when a strange-looking man enters the compartment, dressed in black and wearing dark glasses. When he is told that the sixth seat is taken, he replies, in a deep sepulchral voice, "He won't be coming." He was right. Parador does not come, and his companions never see him alive again. And if Carolus Deena had not taken an interest in the case, the coroner's verdict of suicide would not have been questioned.