A group of strangers is stranded in a boarding house during a snow storm, one of whom is a murderer. Into their midst comes a policeman, travelling on skis. 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! Chalk up another play with superb intrigue for the foremost mystery writer of her time.