After Grace Markway arrives at Hill House, everyone retires for the night, Grace taking the nursery because she is told it is the most haunted room in the house, and she doesn't believe in the supernatural. During the night, the noises and door poundings begin again. It appears to be coming from the nursery but, when they check the nursery, Grace is nowhere to be found. While the others search for Grace, Nell goes off on her own, now certain that she wants to stay forever in the house she has come to both love and fear. She goes dancing from room to room, ending up in the library. She begins to climb the spiral staircase. When she is about halfway to the top, the bolts holding the staircase come undone. Although the staircase is on the verge of collapse, Nell keeps climbing. Markway and Theo call to her to come down, but she keeps climbing until she reaches the platform at the top. Markway climbs the staircase to bring her down. Just as they begin the descent, Nell sees Grace's face peering through a trapdoor in the ceiling. She faints.
Markway decides to send Nell away for her own good. Nell begs to be allowed to stay, convinced that the house wants her, not Grace, and that it will release Grace if it can have her instead. However, Markway is insistent. He packs Nell and Luke into her car. When Luke goes to get the key to the front gate, Nell drives off, telling herself that they can't force her to leave if Hill House wants her to stay. As she drives toward the gate, the car becomes more erratic in its course. Suddenly, Grace Markway appears in the road, and Nell veers head-on into a tree. She is killed instantly. When asked how she got there, Grace explains that she woke up afraid and went looking for her husband. How she ended up in the attic, she doesn't know. She admits to peering through the trapdoor, but she didn't mean to scare Nell. She also doesn't know how she got outside, but she does know that it wasn't because of her that Nell drove into the tree. Luke says that Nell killed herself. Theo believes that Nell got what she wanted and may even now be happy. Markway points out that it was this very tree where the first Mrs Crain also was killed and that he firmly believes Hill House is haunted. Grace only knows that she doesn't want to ever go back inside. Luke thinks the house should be burned to the ground and the ashes scattered with salt.