There is never a dull moment for the Wright cousins, and in this story they are off to explore a large parcel of land that was bequeathed to them after being unintentionally purchased by their great Aunt Opal. It is not easy to arrive at their destination, and both boats and cars take considerable travel time to get there. Once the cousins do arrive, their explorations cause them to stumble upon an old, working submarine that they use to investigate the large lake nearby. As they travel around, the cousins end up discovering not only a nefarious plot that needs to be solved, but they also uncover a hidden and unexpected secret.
This sixth in the Wright Cousin Adventures series continues following the design of its predecessors. Each of the cousins has a unique and memorable personality, and the cousins spend the book working together while occasionally teasing each other with jokes and gentle ribbing. Similar to books like The Boxcar Children, the Wright cousins are resourceful and have all kinds of useful knowledge among them. As a result of this, the cousins are able to solve problems quickly and easily even when those problems have never before been encountered.
As in other books in this series, this book is wholesome in its design and is accessible to both tweens and teens thanks to the approachable language and storytelling used within it. Fans of other books in this series will recognize references made within the text, though this book can stand on its own, as well. Young readers with a sense of adventure and familial connection will appreciate the Wright Cousins and the many stories they have to share. This is a charming addition to libraries for middle grade readers.