This was such an engaging read. I felt like it was more psychological thriller than horror. The ambiguity of the story really helps to create a chilling read that had me hooked. I had the same feeling while reading The Yellow Wallpaper and Other Stories recently, as the characters dove into madness I felt that unease, a prickling along the back of my neck. And Eleanor's final frantic race around the house, dancing along the veranda. And that ending! Jackson has written the story so well that it really allows the readers to make up their own mind - whether Hill House is beset by ghosts, malevolent evil or that Eleanor is in the midst of a psychotic break.