`The horror on the train, great though it may turn out to be, will not compare with the horror that exists here, in this house.` On Christmas Eve, heavy snowfall brings a train to a halt near the village of Hemmersby. Several passengers take shelter in a deserted country house, where the fire has been lit and the table laid for tea - but no one is at home. Trapped together for Christmas, the passengers are seeking to unravel the secrets of the empty house when a murderer strikes in their midst.