Hercule Poirot (David Suchet), the brilliant Belgian detective with the coiffed mustache, unravels another Gordian knot of a mystery in this film based on Agatha Christie's page-turner. Lucy Crale (Aimee Mullins), whose mother was executed for poisoning her bohemian artist spouse, turns up 14 years later armed with a missive that implies her mother was innocent. Poirot agrees to reinvestigate the case, all in the name of justice.