Winifred is a seemingly prim governess living in Victorian England who conceals a psychopathic worldview. She takes a position at Ensor House to tutor the wealthy Pounds children, harboring a secret belief that the estate's master is the aristocratic father who abandoned her. Raised in cruel environments, including a neglectful baby farm, she views the brutality of her society with clinical detachment and dark humor. She approaches her new position with a predatory mindset, masking her true intentions behind formal manners.

The wealthy master of Ensor House and patriarch of the Pounds family. He is an arrogant and tyrannical man who dictates the lives of his family and staff with casual cruelty. He practices the pseudoscience of phrenology, using skull measurements to scientifically justify his prejudices and assert intellectual authority over others. He feels an unwarranted kinship with his new governess upon examining her head.

The insecure and vain mistress of Ensor House. Driven by a desperate need to maintain her physical appearance and social standing, she uses belladonna drops to widen her pupils and constantly polices household behavior. She compensates for her secondary status beneath her husband by inflicting sadistic punishments on those she commands.

The teenage daughter of the Pounds family. She is an observant young woman who quietly absorbs the hypocrisy and strict expectations of her oppressive environment. Frustrated by her parents' tyranny, she nurses conventional aspirations for a wealthy marriage and seeks affection wherever she can find it.

The spoiled son and male heir of the Pounds family. He mimics his father's entitlement, behaving with brutish cruelty toward his sister, the servants, and local animals. He uses his protected status in the household to evade consequences for his violent outbursts.

A young housemaid working at Ensor House. Cheerful, innocent, and kind, she presents a stark contrast to the depravity characterizing the rest of the estate. Her gentle nature quickly draws the intense and predatory attention of the new governess.

The stern housekeeper of Ensor House. Identified by a wandering left eye and a low monotone voice, she acts as a formal gatekeeper for the estate. She is highly observant and committed to maintaining the strict hierarchy of the servant class beneath stairs.

An opportunistic painter hired by Mr. Pounds to occupy his wife's time. He uses ostentatious materials, including a pigment made from real mummies, to impress wealthy clients. Behind the scenes, he manipulates the naive affections of young women in the household to solicit referrals and advance his career.

A clergyman who acts as a replacement father to Winifred after marrying her mother. He establishes a cold domestic environment, identifying a supposed darkness within his stepdaughter from an early age.

A wealthy society woman who visits the Pounds family. She embodies the detached nature of the Victorian elite, treating her infant child more as a status symbol or fashionable accessory than an individual requiring genuine care.

The infant son of Mrs. Fancey. He is temporarily left in the care of Winifred Notty during an afternoon tea party when he becomes fussy.

A holiday guest at Ensor House whose wife is confined at home due to hysterical behavior. He epitomizes colonial entitlement, unwrapping a looted Egyptian mummy as evening entertainment for his aristocratic peers.

A young hall boy working at Ensor House. He moves quietly through the dark spaces of the estate, carrying out tasks assigned by the senior staff.

A lady's maid at Ensor House. She demonstrates a practical awareness of the dangerous consumer goods circulating in Victorian society, specifically the toxic dyes used in high-society fashion.