Boys will be boys, at a boy's school. When a woman is found locked in a closet, it gives someone, intent on murder, an idea for a perfect crime.

A snowstorm traps the guests, proprietors and servants at the newly opened Lynch Cross Moorland Hotel in Yorkshire. Gradually, everyone realizes that a common thread--involving an old crime--links them, and new murders ensue.

Avon Eve, a successful writer for films and television, checks into a spa for a week of rest and relaxation. There, she is assigned a masseuse, Sonja, who the director of the spa calls the Smiler for her constantly pleasant and smiling disposition. Sonia has heard of Avon and is particularly enchanted by one of her works for television - one that Avon thinks is quite dreadful. As they spend more time together, Sonja begins to remember a failed love affair with Sir Jonathan Sibley who claimed to have loved her but refused to marry. When her old love arrives at the spa with his wife - and fails to even recognize Sonja - she becomes unhinged and plays a terrifying game of Russian roulette.

An English, female thuggee operates out of her country house.

On Christmas night, parents leave their psychotic son alone in the house.