Stranger in Our House

Following the car crash that kills her parents, Julia is taken in by Aunt Leslie and Uncle Tom at their California ranch. She relocates with Rachel, Peter, and Bobby, entering a new family dynamic. The move marks the start of a tense adjustment as Julia tries to fit in.

The family notices Julia's painfully shy demeanor and an East Coast accent that seems out of place. To ease tensions and help her blend in, Julia undergoes a makeover to present a more sophisticated persona. The change is met with mixed reactions from the household.

Rachel's horse Sundance suddenly lashes out and tries to trample Julia, leaving her momentarily shaken. After her recovery, Julia begins ingratiating herself into the household and earns cautious trust. The incident foreshadows the growing presence Julia will have in their lives.

Rachel discovers a human tooth among Julia's belongings, a chilling sign that not everything is as it seems. She also finds a missing photo of herself and later discovers hair from Julia's dresser that appears burned. The string of clues deepens her suspicions about Julia's true identity.

Rachel breaks out in hives and cannot attend the high school dance, so Julia goes in her place with Mike, Rachel's boyfriend, borrowing a dress from her. Julia soon begins dating Mike and becomes close to Carolyn, Rachel's best friend. The social shift signals Julia's growing influence over the family.

The day after the dance, Sundance is spooked during a competition, breaks its leg, and a veterinarian euthanizes the horse. The event worsens the eerie mood around Julia and heightens the sense that something malevolent is at work. It also tightens the strain within the household.

Rachel immerses herself in occult books and confers with their neighbor, Professor Jarvis. He hints that there may be black magic at work and warns that something is not right about Julia. This encounter deepens Rachel's fear and determination to uncover the truth.

Rachel phones a friend in Boston and learns Julia supposedly sings in her school's glee club, which clashes with what she has seen of Julia's interests. The contradiction sharpens Rachel's suspicions that Julia is concealing her true identity. The revelations push the investigation toward a dangerous conclusion.

During a hospital visit, Professor Jarvis explains that true witches cannot appear in photographs. The idea of Julia's invisibility in pictures becomes a chilling, tangible clue. The warning intensifies the pressure on Rachel to prove what she suspects.

Leslie plans a road trip and Rachel asks her mother to take pictures of Julia. When the photos are developed, Julia is nowhere to be found in any frame. The film's absence appears to confirm Rachel's fears about Julia's true nature.

Rachel finds a map with burn marks suggesting Julia's plan to cause an accident, and she also witnesses Julia making overt sexual advances on her father. The combination of clues and behavior cements Rachel's conviction that Julia is dangerous. The family braces for what may come during the trip.

Too late to stop the road trip, Rachel develops the film and sees that Julia does not appear in any of the frames. She confronts Julia in the darkroom, where Julia reveals herself as Sarah Brown, the housekeeper, not Rachel's cousin. A fierce struggle ensues and Rachel locks the door to keep Sarah contained.

Sarah breaks out and pursues Rachel, who flees with Mike as they search for her mother. Sarah hits Mike's car, driving them off the road, and the pursuit continues on foot. They eventually spot Rachel's mother, whose car ultimately causes Sarah to drive off a cliff to a fiery explosion.

The Bryant family begins to return to normal life, including adopting a new horse to replace Sundance. In a final twist, another family welcomes Julia into their home, posing as a nanny. The fates of Julia and the family diverge, leaving a changed household and a lingering sense of mystery.