Andrew Winchester is initially presented as a charismatic, successful, and seemingly perfect husband, but he is revealed to be the true antagonist of the story. His abuse is primarily psychological, with a calculated cruelty that relies on manipulation and control rather than brute force. Andrew exerts dominance over both Nina and Millie through surveillance, shifting goalposts, and cruel punishments that break their spirits. His form of abuse is slow and insidious, designed to make his victims doubt their own reality. 

Andrew’s need to dominate others is rooted in the emotional damage inflicted by his mother, who instilled in him a rigid sense of control and punishment. Evelyn’s harsh and unloving treatment created a man who seeks validation through the suffering of others, especially women. His outward charm and success mask his sadism, as he crafts situations where his victims—Nina and Millie—are constantly punished for their perceived failures, even when they follow his orders. This form of abuse, where the rules and expectations are constantly shifting, ensures that his victims can never escape his control. 

Andrew’s sadism is not about brute force but about asserting psychological dominance. His punishments, such as making Nina pull out her own hair or forcing Millie to balance books on her stomach, are designed to humiliate and degrade rather than physically harm. He thrives on the fear and desperation of his victims, making their lives a living nightmare where they can never fully escape his control. Even when Andrew is locked in the attic by Millie, he tries to regain control by offering her money, still viewing her as a maid who can be bought. 

Ultimately, Andrew’s downfall comes not through physical violence but through the psychological torment he inflicts on others being turned back on him. His loss of control, symbolized by the forced removal of his own teeth, mirroring his abuse as a child, is the ultimate retribution for the control he exerted over Nina and Millie.