A group of strangers are stranded in a boarding house during a snow storm, one of whom is a murderer. 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 the drift, and a jurist who makes life miserable for everyone. Into their midst comes a policeman, travelling on skis. He no sooner arrives, than the jurist is killed. Two down, and one to go. The policeman probes the background of everyone present, and rattles a lot of skeletons. Another famous Agatha Christie switch finish!