Superstition and Fear

Supernatural elements like the ghost story of Porthgenna Tower and Sarah's terror of her mistress's oath from beyond the grave drive much of the suspense and character motivation.

Sarah's terror at the moving curtain and her belief that Mrs. Treverton's spirit is watching her drive her actions.

The housekeeper's superstitious remark about another death as a warning to stay away from the house underscores the theme of fear and omens.

Rosamond's terror at the nurse's cryptic words and behavior reflects superstitious dread and the power of unexplained warnings.

Rosamond's irrational terror and the mysterious nature of the warning evoke superstitious dread, contrasting with the doctor's rational skepticism.