A group of strangers—one of whom is a murderer—are stranded in a boarding house during a snow storm. The suspects include the newly married couple who run the house, and the suspicions in their minds nearly wreck their perfect marriage. Others are a spinster with a curious background, an architect who seems better equipped to be a chef, a retired Army major, a strange little man who claims his car has overturned in a drift, and a jurist who makes life miserable for everyone.
Into their midst comes a policeman traveling on skis. He no sooner arrives than the jurist is killed. Two down, and one to go. To get to the rationale of the murderer’s pattern, the policeman probes the background of everyone present and rattles a lot of skeletons. Another famous Agatha Christie switch finish!