A group of strangers is stranded at Monkswell Manor Guest 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 woman with a curious background, an architect who seems better equipped to be a chef, a retired Army major, a strange 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 skiis, whose aim is to protect them from a murderer who has already struck once and who has plans for someone at Monkswell Manor--but who?  He no sooner arrives, when there is a murder. 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. Chalk up another superb intrigue for Agatha Christie, the foremost mystery writer of her time.