The A. B. C. Murders: A Hercule Poirot Mystery Now a Prime original limited series! Agatha Christie’s beloved classic The A.B.C. Murders sets Hercule Poirot on the trail of a serial killer. There’s a serial executioner on the free, working his way through the letter set and the full nation is in a state of panic. A is for Mrs. Ascher in Andover, B is for Betty Barnard in Bexhill, C is for Sir Carmichael Clarke in Churston. With each kill, the killer is getting more confident—but clearing out a few of pondering clues to insult the pleased Hercule Poirot might fair prove to be the primary, and deadly, a mistake.