Jane Baker, Bernice Stegers, a woman living in New Orleans, carries on an affair with Fred Kellerman, Roberto Posse, behind her husband and children's backs. Her adolescent daughter Lucy, Veronica Zinny, suspects the affair. Jane carries on trysts with Fred in an apartment she rents in a boarding house owned by Mrs. Duval, Elisa Kadigia Bove, where her blind adult son Robert, Stanko Molnar, also lives. The fragile balance between private desire and family duty casts a tense shadow over the building, where every sound inside the walls seems to carry more weight than it should.
One night, in a shocking turn of fate, Lucy drowns her little brother Michael in the bathtub and stages it as an accident. When Jane receives the news over the phone, Fred offers to drive her home, but their trip ends in tragedy as they crash into a guardrail. Fred is brutally killed in the wreck, and Jane survives, left to confront the consequences of a crime that will redefine what she is willing to hide.
A year passes, and Jane separates from her husband Leslie Baker, Fernando Pannullo, moving in permanently at the Duvals’ boardinghouse. Mrs. Duval has died in the interim, and the place is now run by Robert alone. On her first night there, Robert invites Jane to dinner but she declines. Instead, she erects a shrine for Fred in the apartment and tends to a mysterious item locked away in a freezer box. That night, Robert hears Jane moaning in a way that suggests something intimate and uncontrolled, deepening the sense that danger lurks behind ordinary routine.
The next morning, Leslie and Lucy arrive for a visit and their reunion feels awkward and strained. Later, Jane agrees to share a drink with Robert, letting him into her apartment while she sits in the bathtub, a space where his blindness complicates the dynamic. Jane flirts with him in a coy, teasing way, asking about his life, while the sounds of her moaning grow louder and more unendurable, prompting Robert to wonder what truly lies behind the façade she maintains.
To uncover the truth, Robert has a friend pull newspaper articles about the car accident and discovers that Jane spent a period in psychiatric care over the past year. The pieces begin to fit uneasily, but Lucy arrives later that day, leaving a photo of her deceased brother on a table inside Jane’s space. Jane senses the intrusion and chastises Robert for allowing Lucy access. A tentative, unsettling flirtation persists between Jane and Robert, but it is quickly pierced by the persistent moaning she emits, now clearly tied to the memory of Fred as she greets his name in the corridor.
On the anniversary of Michael’s death, Jane spends the day at his grave while Robert intensifies his quiet investigation of the apartment. He finds the locked freezer box again and notices pillows arranged under a bedspread in the shape of a person. Lucy comes by for a visit once more, and Robert sends her away. That night, he slips into Jane’s apartment after hearing mounting moans. He passes the bedroom where Jane is masturbating with Fred’s severed head, and after she finishes, she returns the head to the freezer, where it is discovered by Robert.
Lucy overhears a tense phone call between her father and Robert, and she tries to press Robert to reveal what he knows, but Leslie dismisses it as fantasy. Lucy confronts Robert, then breaks into the apartment and finds Fred’s severed head, though she tells him that he has imagined it all. The family tension erupts during a weekend dinner when Lucy has prepared soup for them all. Jane finds an earlobe in the broth and realizes that Lucy has used flesh from Fred’s severed head in the recipe, a gruesome revelation that confirms Lucy’s murderous act against Michael. Lucy confesses to having murdered Michael, and Jane, in a fury, strangles Lucy and drowns her in the bathtub. Robert, who tries to come to Lucy’s aid, is pushed down the stairs by Jane and loses consciousness.
Jane retrieves Fred’s severed head from the freezer and begins kissing it with a feverish intensity. Robert regains his senses and attempts to phone the police, only to discover that the cord has been cut. He enters the apartment to confront Jane, who violently attacks him, but he manages to kill her by smashing her face into the hot oven. He cries out for Lucy and crawls toward Jane’s bed, where the severed head of Fred suddenly rises and attacks him, sinking its teeth into his neck as the horror of the moment closes in.
