The arrival of a mysterious housekeeper disrupts the tranquil life of Felicity Dawlish, wife of a high-ranking police official, triggering a sequence of unsettling events. Felicity Dawlish, married to Patrick Dawlish, the Deputy Assistant Commissioner for Crime in London, seeks domestic help, only to find her household compromised by a stranger. The narrative follows the subsequent investigation as the couple faces threats that challenge their security and professional standing. The story operates within the framework of a traditional police procedural, emphasizing the intersection of personal vulnerability and public duty.

Readers frequently highlight the author's ability to maintain a steady pace within the classic British crime tradition. Discussion often centers on the domestic vulnerability of the protagonist and how it contrasts with the professional authority of her husband. Critics note that the narrative relies on character dynamics to drive the suspense rather than relying solely on action sequences. The work is often cited for its period-specific atmosphere and the effective integration of personal stakes into a broader criminal investigation.