There is a ghost that is in the school bathroom. Haha. And they are trying to get it out. So, they make a potion, but there needs to be some of Nancy's hair in it. Haha. So, at night time when Nancy is sleeping, Bean cuts off a little tiny bit of her hair. So then they pour it around the bathroom because the potion makes no one go back to it. At the end of the book, Bean is like, "Nancy, did you get a new haircut?" And Nancy is like, "No," and runs inside to look in the mirror.