After 45 years, Margaret Sutton's young detective, Judy Bolton, returns for her 39th mystery adventure. At the end of "Secret of the Sand Castle", the author gave the title of the next book in the series. It was never written until now. Based on conversations with Margaret Sutton and her family, plus extensive research, the magic of Judy and her friends was recreated by co-authors Kate Duvall and Beverly Hatfield in this book. Judy and her friends find themselves pursuing a criminal who resembles Judy's husband. Courage and keen observation are Judy's trademarks, and they prove her up to the task once again.