Distraught about her childhood nanny's murder and fearing that she may responsible for the woman's death, heiress Norma Restarick (Jemima Rooper) turns to Belgian-born sleuth Hercule Poirot (David Suchet) for help unraveling the crime. After settings his "little grey cells" to work on the matter, Poirot enlists the aid of author Ariadne Oliver (Zoë Wanamaker) in this twisty whodunit based on Agatha Christie's novel.