John Malkovich stars as an older but wiser Hercule Poirot as he investigates the source of a series of sinister letters written by a mysterious criminal in the early 1930's in England. Although he is no longer revered, when murders begin occurring in relation to the letters, Poirot takes the case into his own hands and deploys his detective skills in order to find the killer before they strike again. Malkovich stars alongside Rupert Grint and Andrew Buchan in this three-part crime-drama series.