The film primarily takes place in a spooky old Victorian house in the suburbs of Los Angeles. Lucy, the protagonist, is a therapist and a social worker who has just moved into the house with her husband, Wade, and their baby daughter. However, strange things start happening almost immediately, such as the sound of a baby crying in the middle of the night, and Lucy's belongings being moved around without explanation.
As Lucy investigates the history of the house, she learns that it had been owned by a family with a disturbing past. The father had been abusive towards his wife and children, leading to a tragic incident in which the wife and children were killed. This incident left a dark stain on the house, and the spirits of the deceased have never left, causing headaches for the new occupants.
Lucy, being a therapist, decides to try to help the troubled spirits move on, but her efforts only seem to make things worse. The ghosts become more aggressive and menacing, leading to a series of increasingly terrifying encounters between the living and the dead.
As the plot thickens, Lucy realizes that the ghosts are not interested in being helped. Instead, they want to use her and her family as a means of escape from their torment. The film climaxes in a thrilling sequence that sees Lucy and her family fighting for their lives against the malevolent spirits that haunt their home.
Overall, The Occupants is a chilling and suspenseful movie that will keep you on the edge of your seat. The strong performances of the cast and the spooky atmosphere of the house make for a thoroughly engaging supernatural thriller.