The Witches (1966)

Fontaine stars as teacher Gwen Mayfield, who is in charge of a missionary school in Africa. A witch doctor puts a curse on her, and she has a nervous breakdown. Returning to England, she takes a job running a small rural school. In the village, there is an active voodoo cult. They have targeted a young woman named Linda (Ingrid Brett), whom they plan to offer as a virgin sacrifice. The cult members are led by journalist Stephanie Bax (Kay Walsh), whom Mayfield discovers is the head witch. Mayfield's student Ronnie Dowsett (Martin Stephens) is being harassed by the cult to keep him from protecting Linda, his girlfriend.