Loner Mark Lewis works at a film studio during the day and, at night, takes racy photographs of women. Also he's making a documentary on fear, which involves recording the reactions of victims as he murders them. He befriends Helen, the daughter of the family living in the apartment below his, and he tells her vaguely about the movie he is making.
A young governess for two children becomes convinced that the house and grounds are haunted by ghosts and that the children are being possessed.
A team consisting of a physicist, his wife, a young female psychic, and the only survivor of the previous visit are sent to the notorious Hell House to prove or disprove survival after death. Previous visitors have either been killed or gone mad, and it is up to the team to survive a full week in isolation, and solve the mystery of the Hell House.
