Michael Parkinson introduces 'Ghostwatch', a live broadcast investigating a reportedly haunted house at Foxhill Drive in Northolt. He is joined in the studio by parapsychologist Dr Lin Pascoe and by co-presenter Mike Smith, who is supervising phone calls from the audience. At the house, Craig Charles talk to the neighbours while Mike's wife Sarah Greene goes into the house to meet its residents, Pam Earley and her two daughters, Suzanne and Kim. Pam has tried unsuccessfully to sell the house since ghostly appearances and loud unexplained banging noises began almost a year ago.

Dr Pascoe shows video footage of a 'psychic event' in the girls' bedroom taken a few months earlier. Members of the public call in to say they think they can see a ghost in the video. Kim explains that after the unexplained noises, they named the ghost 'Pipes'. She claims to have spoken to 'Pipes', who, she says, lives in the cupboard under the stairs, the door to which Pam has now boarded up. Dr Pascoe shows stills and video footage from her investigation into the Earley family's experiences. Emilio Sylvestri comments on the evidence by satellite link from New York and expresses the opinion that Pascoe's evidence proves nothing and could in fact be explained rationally.

Craig talks to the neighbours, who tell him that there have been unexplained child disappearances in the area and that a dog was killed nearby. He also interviews a man who tried to help exorcise the ghost, without success. There is banging inside the house and Sarah heads upstairs to check on the girls, but Parkinson stops her. The closed circuit cameras in the house caught Suzanne getting out of bed but she never reached the landing. Using the cameras, Pascoe locates Suzanne, banging on the pipes. Parkinson is sure it is all a hoax. Sarah and the camera crew hear cats meowing, but aren't able to pinpoint the source of the noise. Instead they find Suzanne unconscious, her face covered in scratches. A caller says that a childminder used to live in the Foxhill Drive area many years before and that she killed several children. Sarah and the crew decide to leave the house with the family. As the camera pans across the room, a man is briefly glimpsed.

The banging noises begin again and become so violent that a picture frame falls off the wall and breaks. Suzanne cowers behind an armchair and begins to speak in a deep voice that is not her own. Sarah hears cats meowing from under the stars and begins to pry the cupboard open when a mirror falls over and lands on the soundman. Kim begins to scream as the TV signal is interrupted. When the images return, Sarah and the crew are seen playing happily with the girls in the living room.

A man phones to say that in the 1960s the owners of the house sublet the house to their nephew Raymond, a convicted child molester. Claiming that his body would be taken over by the spirit of a woman, he eventually hanged himself under the stairs while the owners were on holiday. He had his many cats in there with him and eventually they got hungry and fed on his body. Pascoe realises that the images from the house cannot be live but must be from earlier on as the broken picture is back hanging on the wall again. She is convinced that the ghost is in the machinery, which has in effect channelled its energy. The power in the studio is knocked out.

The house is evacuated while Sarah keeps looking for Suzanne. She goes in the cupboard under the stairs and the door slams behind her. There is the sound of cats screaming. Back at the studio Parkinson wanders in the darkness. He begins to speak in a deep and threatening voice that is not his own.