Excuse the double posting of reviews. I'm counting this towards the Read the Book, See the Movie Challenge.
The Hidden Staircase
Nancy is asked by her friend Helen Corning to investigate some mysterious goings on at her aunts' house. Between the ghostly hauntings and the disappearance of Nancy's father, she certainly has her hands full with this mystery. Helen plays a fairly prominent role as Nancy's helper, but she doesn't really do any deducting. That's all left to Nancy as she is the braver, smarter one. And, of course, the young sleuth solves the mystery to everyone's satisfaction with her usual style and poise.
Nancy Drew: The Hidden Staircase
While you would think that this would have some relation to the book it is titled after, you would be wrong. There are two sisters named Turnbull and that's about where the similarities end. Because of some weird stipulation in their father's will, at least one of the sisters has to spend every night in the house for 20 years before they own it. Nancy sticks her nose where it doesn't belong when a man is murdered at the Turnbull's place. She blatantly meddles in a police "investigation" when she makes Ted write a suicide note so the sisters will stay in their mansion and not give up their eligibility to outright own it and then give it up for a children's hospital. She gets Ted in trouble a whole lot and, in the end, he is the one who rescues them both with his cleverness.