The story is about a young couple, Mollie and Giles Ralston, who have started up a new hotel in the converted Monkswell Manor. They are snowed in together with four guests and an additional traveller, who ran his car into a snowdrift. Detective Sergeant Trotter arrives on skis to inform the group that he believes a murderer is on his way to the hotel, following the death of Miss Maureen Lyon in London.
When one of the guests â Mrs Boyle â is killed, they realize that the murderer is already there. Although the suspicion falls first on Christopher Wren, an erratic young man who fits the description of the supposed murderer, it quickly transpires that the killer could be any one of the guests, or even the hosts themselves.