Susanna Pleydell finds her marriage to the dashing Aubrey St. Clare unraveling into a nightmare of addiction and occult influence after they return to London from India. Susanna, a woman with a natural aptitude for nursing, must navigate the treacherous social and domestic landscape of her new life. She faces the manipulative presence of Dr. Damien Adar, who exerts a dark control over her husband. The narrative unfolds through Susanna's perspective, detailing her struggle to reclaim her autonomy and protect her household from the encroaching shadows of her husband's secret life.

This novel reflects the hallmark style of Victoria Holt, emphasizing atmospheric tension and the classic gothic trope of a woman trapped in a house of secrets. The narrative relies on the slow revelation of character flaws and external threats to build a sense of mounting dread. Readers often note the effective contrast between the protagonist's professional competence and her personal vulnerability in the face of her husband's decline. The story serves as a representative example of mid-century gothic romance, prioritizing psychological suspense over overt action.