In the bustling city of Los Angeles, single mother Carla Moran finds her life turned upside down when a malevolent, unseen force violently assaults her within the sanctity of her home. This horrifying experience is just the beginning, as strange occurrences escalate, compelling Carla and her children to seek refuge with her closest friend, Cindy Nash. When they return to their home, it becomes clear that the terror is far from over; in a shocking incident, Carla's car inexplicably veers out of control while driving, nearly resulting in a catastrophic accident.
As Carla's mental state rapidly deteriorates, Cindy convinces her to visit a psychiatrist, leading to an appointment with Dr. Sneiderman. Initially reluctant, Carla ultimately agrees to undergo therapy following a particularly harrowing episode where she is attacked in her bathroom, leaving physical evidence of her injuries—bite marks and bruises that are difficult to explain.
During a drive home from therapy, Dr. Sneiderman meets Carla's children and unravels the painful past that haunts her, including incidents of sexual and physical abuse, a teenage pregnancy, and the tragic loss of her first husband. At first, he attributes her paranormal experiences to her psychological trauma, but he decides to keep an open mind at Carla's urging.
However, the next encounter with the entity reinforces Carla's fears as she is attacked right in front of her children, who bravely attempt to intervene but suffer physical repercussions, including her son's broken wrist. This incident plunges Carla deeper into helplessness.
During a staff meeting led by Dr. Weber, skepticism reigns as he questions Carla's experiences, attributing them to her troubled psyche and self-destructive tendencies. That night, Carla unknowingly falls victim to the entity's manipulation, experiencing an unsettling episode of intimacy while asleep, orchestrated by the supernatural force. Following this, Dr. Sneiderman suggests hospitalization for observation, a recommendation that enrages Carla, especially as he implies she harbors inappropriate feelings for her son.
With the haunting events still looming, Cindy's intuition drives her and Carla toward the supernatural realm. A serendipitous meeting with two parapsychologists at a bookstore sets the stage for a significant investigation at Carla's home. Although initially skeptical, they are soon drawn into the bizarre occurrences and agree to collaborate with Dr. Cooley, the lead investigator. When Dr. Sneiderman arrives, he attempts to convince Carla that her experiences are the fabrications of her mind, but she firmly dismisses his concerns. With newfound seriousness surrounding her case, Carla begins to experience a sense of relief.
As she navigates her chaotic life, Carla's boyfriend, Jerry Anderson, witnesses a particularly disturbing event that causes him to regard her situation with fear. This confrontation leads to a confrontation with Carla's son, who, believing Jerry to be the threat, makes a desperate move against him, ultimately resulting in Jerry ending their relationship in terror.
In search of answers, Carla agrees to participate in an ambitious experiment devised by Dr. Cooley's team, aimed at capturing the entity by recreating her home and using liquid helium to freeze it. However, just as the experiment is about to commence, Dr. Sneiderman tries to persuade Carla to reconsider, revealing more about his personal interest in her plight. When the entity reveals itself, instead of succumbing to the trap, it turns the liquid helium jets against Carla. Undeterred, she boldly claims that while it may take her life, her soul belongs to her alone. With a dramatic explosion, Dr. Sneiderman rushes to save her from imminent danger.
Ultimately, the team believes they have contained the entity within a sizeable block of ice—until it breaks free and vanishes without a trace. Dr. Sneiderman is left to grapple with the truth of Carla's experiences. On the following day, as Carla steps back into her home, she is plagued by the ominous sound of her front door slamming shut, accompanied by a menacing whisper: > "Welcome home, cunt." Calmly, she exits the house with her family, determined to escape the entity's grasp.
In a cautious conclusion, a disclaimer reveals that Carla had moved to Texas, where she continues to encounter sporadic, albeit less intense, assaults from the elusive entity.
