The Open House follows a teenage boy named Logan Wallace and his mother, Naomi, as they move into a new house following the sudden death of Logan's father. While the house seems idyllic at first, they soon begin to experience strange occurrences and gradually become trapped in a nightmare.
The unexplained events begin with small things like doors being left open and the shower turning on by itself, but soon escalate to more frightening occurrences such as mysterious figures lurking in the shadows and strange noises coming from the basement. As they try to figure out what is happening, they begin to suspect the presence of a malevolent force in their home.
As the days go by, Logan and Naomi find their home invaded by unknown people who seem to be watching their every move. Their phones and internet are cut off and they are left with no way of calling for help. They begin to feel trapped and isolated in the house, unsure of who to trust and what is real.
As the situation worsens, the tension between Logan and Naomi increases, threatening to tear them apart. With no help in sight, they are forced to confront the evil that has taken over their home and fight for their survival.