Agatha Christie's 1936 mystery, The A.B.C. Murders, pits a serial killer against Christie's renowned Belgian detective Hercule Poirot and his assistant and friend Hastings. The book's second murder follows the alphabetical conventions of the first murder: Elizabeth Barnard, known as Betty, was killed in the town of Bexhill. Though Poirot had been alerted to the planned murder in Bexhill ahead of time, the killer murdered Betty shortly after midnight on the promised date. An A.B.C. railway guide was placed with the body, as with the first murder victim, indicating that this murder was committed by the same person.

To gain insight into the victom's personality and behavior, Poirot questioned a Bexhill detective, Betty's boss, a fellow waitress, her parents, her sister, and her fiancé. Clues he found important were that Betty was strangled with her own belt, that she was pretty, and that her sister considered her "an unmitigated little ass" who flirted widely despite being engaged. Poirot refers to the "amazing magnanimity of the murderer," puzzling Hastings and Betty's relatives, then enlists the help of Betty's sister and fiancé in continuing to investigate the series of murders. A third soon follows in the same alphabetical pattern, then a fourth that breaks the pattern and helps Poirot and the investigative team place all the clues in their proper order.