 A Catholic reverend, Will Smythe, and his followers are chased out of town after Smythe is accused of adultery and polygamy. Joined by a rugged woodsman, Marion Dalton, who wants his cheating wife, the group ventures into a valley, where dwells an ancient evil spirit. As members of the group start to disappear, the witch-bred, insane Leah must discover how to thwart the spirit.