In The ABC Murders, Hercule Poirot gets a taunting letter warning him to look out for Andover on a certain date, signed “ABC.” Of course, someone is murdered on that date, and an ABC Railway Guide is found near the body. More murders follow, and Poirot must track down an apparent psychopath.
As usual, I listened to this as a radio play, so I’m not sure whether the presentation of a particular form of misdirection originated in the book or in the adaptation. The misdirection worked almost too well: I said to myself, “ugh, is this the kind of story we’re getting?” and stopped giving it my full attention. It seemed to end satisfyingly, however, and in a way consistent with the characters. I should remember that my skepticism apparently is reduced when I’m tired.