Jill drives to the mansion now being used by Ryan Electric products and is almost crushed by two of their removal vans as she enters the grounds. Collinson meets Peter as he arrives and the rest of the research team arrives shortly afterwards. Peter shows them around their new top-secret research facility. They are to work on a new type of recording medium in attempt to beat the Japanese competition. Jill will correlate their research using complex computer programmes. Collinson tells Peter that the computer storage room isn't ready after all. The men have refused to do any work there. Peter pulls off some of the rotting wood panelling and reveals a set of stone stairs that don't seem to go anywhere. They have apparently been there since Saxon times and the house has been built around them. Jill, left alone, suddenly hears a scream. She collapses and is helped by Peter and Collinson. Peter is convinced that she is subconsciously trying to get his attention as he has been cooling off from their affair recently.

Peter takes Jill to the local pub and Alan, who works there, admits that he used to play at the mansion as a child. They go to see the vicar, who tells them that the previous owners made an application for exorcism. Collinson confirms this, explaining that it was granted in 1892, two years after the death of the maid Louisa after falling from the stairs in the room. As the workers refuse to refurbish the room, Peter, after hearing the screaming himself, decides to find out where it comes from . The team attempt to record it, but their equipment only registers them, not the screaming. Jill, however, actually sees Louisa at the top of the stairs. Alan is invited to visit, but he flees in terror once the screaming starts. He says that when his friend Jacky was inside, he was visited not just by Louisa but also by others.

Jill calculates that there have been 8,000 appearances since Luisa's death. The team try again to record the phenomenon using heat sensors, but are again unsuccessful, although this time two people see the maid. Crawshaw is developing a new washing machine for Ryan but Peter won't let him use any of his space. Jill has a breakthrough, positing that the room itself acts as a recording device but that it depends on the individual's sensitivity. Peter tries to control the visitations with vibrations and pushes his team to the point of physical and mental exhaustion. Pushed by Ryan, he has promised to deliver results soon. Jill's computer starts typing out individual words like 'pray' and 'soul'. When Peter's experiments fail after bombarding the room with sound, it becomes clear that he has, in effect, 'wiped' the recording from the stone.

Crawshaw is installed by Ryan in the mansion as Peter's results have been to slow in coming. The men go back to fitting out the room for the computers now that the screaming has stopped. Jill is now sure that Peter has only erased the top layer, and there is something far older beneath it that he may have energised with his experiments. He refuses to listen to her and insists she take some leave. Jill goes to the room and is surrounded by ancient elemental forces. She goes up the stairs and reaches an ancient sacrificial site that used to be there. She falls to her death. At the inquest, Peter says that she was unstable. He has all her work shredded as she was exploring the possibility of looking at elements from 7,000 years ago. He refuses to take any responsibility for what happened to her, and Collinson hits him. Peter visits the room again and is pursued by the sounds of Jill screaming for his help.