A character who travels only by train at night.
Do not write about the daytime.
The character must be on the way to an appointment.
They prefer to be alone, so any other characters they meet must quickly exit the story in any way you see fit.
The character is carrying something they are compelled to protect.
Once the character gets off the train, the story must be nearing the end.
The character must have an epiphany or a secret must be revealed.
The character feels more at home travelling than staying anywhere in particular.
The character must have at least one quirk that is explainable, and at least one that is inexplicable.
The story must at least begin or end with at least one death.