From the Publisher:
When a rich city kid disappears from nearby Camp Whispering Pines, the three cousins find themselves in the middle of a serious mystery. A ransom note raises the stakes, and the police start tracking down a kidnapper. But Jeff, David, and Claire learn that the boy was last seen headed toward fabled Skull Cliff, possibly in search of its sparkly treasure. The clues just don't add up. As they put all of their evidence together, the cousins start to believe that there never was a kidnapping. But that doesn't mean the boy is out of trouble. He's in more danger than ever
Kristiana Gregory writes historical fiction and is best known for her Dear America series. She does a great deal of research for her books, visiting the places she's going to write about and finding out useful information such as what the weather was like, or what people thought about, by looking through journals and almanacs of that time. Kristiana feels that her readers can relate to the characters in her book because the problems they deal with--learning to make good decisions or getting through hard times--are universal.