In Book 4 of the Sherlock Jones, Jr. Detective Series, Sherlock Jones: The Phantom Airplane by Ed Dunlop, Penny and Sherlock feel they have landed in the lap of luxury when they are invited to vacation in the plush lakeside lodge of a wealthy friend. But soon they begin to uncover the secrets of some shady activity at a neighboring estate, and their investigative zeal gets them a little too close to suspected illegal activity in this popular Christian fiction adventure. Boys especially will love the action and suspense in this fast-moving plot.
This was my favorite in this series. You can read each as a stand-alone novel, though there are a few minor characters that have arcs started in the previous book.
I loved the pictures I saw in my head of the scenery around them. These books have unique mystery plots, but the characters are a little flat.