Dr. David Marrow, a renowned psychologist, conducts a study on fear and insomnia that draws in three participants, each with their own sleep-related issues. The group is told that they will be staying in a lavish, isolated mansion while their sleep patterns and responses to stress are observed. However, the true purpose of the study is to delve into the psychological aspect of fear, unbeknownst to the participants. The vast estate, Hill House, with its dark history and foreboding atmosphere, serves as the perfect setting for this investigation. As the participants settle in, they begin to explore the elaborate and eerie mansion, which boasts an intricate design and is filled with unsettling statues and ornate furnishings.

As night falls, strange occurrences start to unsettle the group. The mansion's dark past begins to surface when they hear unexplained noises and witness terrifying visions. It becomes clear that Hill House harbors more than just secrets; it is haunted by the memories and ghosts of its troubled history. The participants, along with Dr. Marrow, must confront the supernatural forces at work. Initially skeptical, they soon cannot deny the haunting around them as it intensifies, challenging their sanity and revealing the menacing nature of the mansion. Fear takes hold, and the boundary between reality and the paranormal blurs as they struggle to understand the true nature of Hill House.