The Devil's Den by James Babb is due to be published in September 2017. It is the third book in his series and contains a real life treasure hunt.

It looks like the hunt is on for a treasure box hidden by the characters in the books. According to the website, it is hidden in Fort Smith and you can use clues in this series of books to find it.

More details here:

Announcement - Treasure Hunt Starts Soon

About the Treasure