Norah Lofts

In a mission in China in 1935, Agatha Andrews (Margaret Leighton) is a rigid missionary beset by Mongolian bandits led by Warlord chief Tunga Khan (Mike Mazurki). (imdb)

After being threatened by witchcraft in Africa, Gwen Mayfield has a nervous breakdown and returns to England. She is invited to teach in a private school, owned by the wealthy Alan Bax and his sister Stephanie Bax, in the village of Heddaby. After a period in the place, she witnesses weird events with locals, and she realizes that the place is indeed a coven and her student Linda Rigg is being prepared for a sacrifice. (imdb)

A woman is haunted by her conscience after she accidentally kills her lodger and hides the body.