Title: The Message in the Hollow Oak (Nancy Drew #12) by Carolyn Keene Pages: 181 Genres: Mystery, Children’s Publisher: Grosset & Dunlap (1972) Summary: A group of professional detectives challenge Nancy to tackle a mystery that they have failed to solve: find an invaluable message hidden by a missionary centuries ago in a hollow oak tree in Illinois. While searching the woods for the ancient tree, Nancy and her friends live with a group of young… Read More