Maryann is a teenager who finds herself alone after her parents die in an accident. Her grandparents take her in, but she struggles to find a place in her new home. One day, while exploring the woods near her grandparent's house, she stumbles upon a neighboring family's home. She is immediately drawn to the boy who lives there, Andy, who is bedridden due to a mysterious illness.
Despite Andy's mother, Katherine, forbidding her from entering the home, Maryann persists in visiting Andy. As their friendship grows, Maryann begins to notice that there is something off about the family, especially Katherine. She overhears strange conversations and sees her giving Andy injections that seem to make him worse.
Eventually, Maryann discovers that Katherine is a doctor who is conducting medical experiments on Andy, pushing him to the brink of death in the hopes of finding a cure for his illness. Maryann feels compelled to help her friend, even though it means going against Katherine and putting herself in danger.
As she delves deeper into the family's secrets, Maryann uncovers a web of lies and desperation that shocks her to her core. She is forced to confront the truth about the people she trusted and make a decision that will change her life forever.