Mollie and Giles Ralston are opening their guesthouse, Monkswell Manor, for its first guests. They are new to the business and struggle with the details and an unusually heavy snowstorm. They hear on the radio that a Mrs. Maureen Lyon has been murdered in London and the suspect is wearing a dark overcoat, light scarf, and soft felt hat. More guests arrive, as does a police sergeant who kindly tells them that the killer is on the loose and all could be suspects. What follows next is an iconic and beloved classic that will leave you guessing again and again.