The world's greatest detective, Hercule Poirot - legendary star of Agatha Christie's Murder on the Orient Express and Death on the Nile - puts his little grey cells to work solving a baffling Christmas mystery. Sophie Hannah is the author of The Monogram Murders, the first Hercule Poirot novel authorized by the estate of Agatha Christie, and its sequels Closed Casket, The Mystery of Three Quarters, and The Killings at Kingfisher Hill. The world's most beloved detective, Hercule Poirot is back!