The newest published book in the Windmill Pete Series is The Mysterious Stranger.
This book introduces the whole gang and tells about them setting up their clubhouse rules. In the midst of that process, the gang sees a mysterious stranger, an older man who is watching them. The man leads them to a haunted-looking house, which takes them to a closed door, which leads them to the bottom of some stairs, and then on to the local hospital. It’s there that Chip meets a new family who is moving to town, bringing two key actors into the upcoming dramas.
One special aspect of The Mysterious Stranger is its description of the woods, cliff and stream where many of the gang’s adventures take place. For those who grew up in the author’s home town, the description may bring back good memories of a special time and place in their youth.