The short story "The Extra Passenger” by Stephen Grendon represents a genre of comic horror tales. The plot includes the story of preparing the murder and what happened after that.
This is the first line: "Mr. Arodias had worked a long time on his plan to kill his eccentric uncle, and he was very proud of it." Mr. Arodias bought the ticket for the train, he decided to commit the crime during the time when he left the train on one station and came back on the next. He expected that it would be an excellent alibi and it could be. But unexpectedly when he returned back to his compartment in the train, the new passenger appeared. This extra passenger kept silence, suspicion of the plot started to increase dramatically.
It is interesting how grammar constructions in English can help to highlight the tense
"Mr. Arodias was suddenly aware that his traveling companion had been speaking of his uncle for the past few minutes in the past tense".
What happened next, the readers can know from the story. This is a link for the text:
This is a short movie about this story: