Mystery in the Pirate Oak — Helen Fuller Orton

If only the old oak tree could talk? Perhaps it could answer the questions that puzzle Chad and his sister, Ellie.

Is a pirate treasure really buried here? Why is there a strange light near the tree at night? And what about the silver box? Grandmother Hale insists she left it in a hollow of the tree sixty years ago! Why is the box so important?

Then suddenly it looks as if they will never know the secret of the tree. For one day on their beloved oak a sign appears: NO TRESPASSING!