I found myself wondering, and no one else I think has suggested this, whether Faraday himself is an influence on the poltergeist activity at Hundreds - if indeed we accept that something supernatural has taken place. He has links to the house through his mother, he has been interested in the house since childhood and he seems to have conflicting feelings towards the inhabitants of the house. The chemistry between himself and Caroline is very odd, they repel each other as much as they attract, and the supernatural activity begins with his entrance into the story. As narrator, can he be relied upon? This was a real page-turner, and I would definitely recommend.