اتفاقات این سریال کوتاه 3 قسمتی که در سال 1930 رخ می دهد درباره رویارویی هرکول پوآرو با قاتلی سریالی به نام A.B.C می باشد 1933. Hercule Poirot, older and greyer, receives letters threatening murder. The sender signs themselves only as “A.B.C.” When he takes the letters to the police looking for help, Hercule finds all his old friends have moved on. But soon there is a murder and the once-great detective must take matters into his own hands.