Treasure Hunt (Book 6)
Billie and the Secret Mystery Club have been given a very important mystery to solve for the principal at school. A long time ago, a time capsule was hidden in the school somewhere, and it's up to the SMC to find it!
Series: A Billie B. Mystery
A slightly older Billie, her best friend, Jack, and other familiar friends from the original series, solve mysteries at school and in the neighborhood.