The Message in the Hollow Oak

The Message in the Hollow Oak, by Carolyn Keene, is a Nancy Drew mystery that is 182 pages long.  In this book, Nancy's Aunt Eloise tells her that she knows a detective named Boyce Osborne who has a mystery for her.  When she gets to Aunt Eloise's house, her aunt introduces her to Boyce, and Boyce tells her about the mystery.  He says he was solving a case about a hollow oak. The oak had a message inside it. The message was on a lead plate and it said PF, and there was an arrow under it pointing east.  Boyce says that before he could finish solving the case, he had to return home.  Later Nancy tells Ned and he says that he has a cousin that is going to work at a dig near were she is going, so Nancy goes to meet her.  She takes a plane and meets a man named Kit who is very rude.  After she gets off the plane, she meets Ned's cousin, Julie Anne, but she also runs into Kit again.  Then, a lady tells Nancy that Kit is a troublemaker.  Nancy goes to the dig and goes to sleep, but then she wakes up and hears a voice that says, "Nancy Drew, Nancy Drew".  After looking around, she spots a goat in the corner of her room eating some cookies.  After this, Nancy starts to think that Kit is up to no good.