This is a recurring motif partly of Franklin Clarke’s own devising. He signs the letters to Poirot “ABC” and leaves a railway guide of the same name at the scene of all his crimes. This is part of his scheme to disguise himself as a maniacal serial killer, rather than a greedy man seeking to conceal his desire for his brother’s fortune. Poirot suggests that the killer is “railway-minded” and immature and points out that Franklin had recently been reading a classic of children’s literature, E. Nesbit’s The Railway Children (246).

The plot itself is partly driven by train trips, as Poirot and Hastings travel to Churston by rail, discussing the complexities of the crime, as it appears this set of murders is very different from their usual investigation of more personalized crimes. This crime holds the key to the series, so it is suggestive that they first visit the scene by rail. This train, after all, takes them to their first meeting with Franklin Clarke.

Christie periodically uses clothing to signify aspects of a character’s nature. Thora Grey strikes Poirot with her attention to fashionable dress—“that crepe marocain and the silver fox collar—dernier cri [the latest fashion]” (148).