From the ITV press release:
World-famous sleuth Hercule Poirot has just solved a complex case in Istanbul for the British Army, when he witnesses an act of brutal injustice on the streets. Relieved when a new case calls him back to London, Poirot’s old acquaintance Xavier Bouc (Serge Hazanavicius), secures him a last minute ticket on the luxurious Orient Express.
Among the eclectic range of passengers are Princess Dragomiroff (Dame Eileen Atkins) and her nervous maid Hildegard Schmidt (Susanne Lothar), English Governess Mary Debenham (Jessica Chastain) and Swedish missionary Greta Ohlsson (Marie-Josée Croze).
Whilst aboard the train Poirot is approached by ruthless American businessman Samuel Ratchett (Toby Jones) who offers him $10,000 to watch his back. Could Ratchett be fearful of the Italian Antonio Foscarelli (Joseph Mawle), English Colonel John Arbuthnott (David Morrissey), pushy American Mrs Hubbard (Barbara Hershey) or Hungarian diplomat Count Andrenyi (Stanley Weber) and his wife, Countess Andrenyi (Elena Satine)? Poirot awakes the following morning to find the train stuck in a snowdrift and Ratchett dead in his compartment
With nothing but a scrap of paper to go on, Poirot must piece together Ratchett’s identity before he can establish which of his fellow passengers murdered him and their motive.
David Suchet says: “It's an honour to have such a wonderful international cast on board for this world famous murder mystery. Writer, Stewart Harcourt, has created an exquisite script. His attention to detail is impeccable.”
Producer Karen Thrussell says: “We’re all incredibly delighted that 21 years after David Suchet first played Hercule Poirot he is now starring in arguably the most ingenious and best loved Agatha Christie title of all time.”