Every single day follows a strict routine: cleaning the stunning estate from top to bottom, picking up the daughter from school, and cooking a meal before retreating to a tiny, locked room on the top floor. Yet, underlying tensions quickly surface. The protagonist tries hard to ignore how Nina Winchester deliberately makes household messes just to watch her clean them up, tells bizarre lies about her own child, and how her husband, Andrew, appears more emotionally broken with every passing day.

 Drawn to Andrew's kind, sorrowful eyes, The Housemaid soon finds herself dangerously imagining what it would be like to take Nina's place—enjoying the luxury walk-in closet, the expensive cars, and the seemingly ideal husband. However, that fantasy quickly shatters as hidden truths come to light. She soon discovers that the glamorous Winchester household harbors secrets far more sinister and dangerous than her own, leading to a tense game of survival where nothing is as it appears.