Letters signed ABC announce each killing before it happens, taunting Hercule Poirot with a pattern he cannot yet break.
This is among Agatha Christie's most admired Poirot novels, built on a premise that looks mechanical and proves to be anything but. Victims are selected by alphabet, the towns follow the same order, and a railway guide is left at every scene. Poirot works against a correspondent who appears to be writing the case as it unfolds, and the deduction turns on noticing what the pattern has been designed to hide. The misdirection is widely counted a high point of the genre.
On the page:
• A Hercule Poirot investigation across several English towns
• Anonymous letters announcing each crime in advance
• A serial structure used as a device rather than a formula
• Captain Hastings narrating much of the case
For readers of golden age detective fiction and followers of Poirot, available at Boipoka.