I received a copy of this book in return for an honest review.This is a fantastic beginning to a mystery series for children aged 9 to 12. I absolutely loved it!Jeff Douglas is a fantastic character. He is a curious eleven year old. I loved his inquisitiveness and bravery. When he sees some unusual activity on the nearby Battleship Island, he does what every curious boy does - he investigates.This is an exciting mystery/adventure that captured my attention from the first page! I love mysteries - trying to solve the puzzles to find out who, what, when and how is a passion of mine. When I started to read this book, I was reminded of the mystery stories I loved to read as a child, mostly the Famous Five, Nancy Drew and The Hardy Boys series. I realised that I miss reading these types of books. Note to self: Read more mysteries in future! I love the action/adventure/danger aspect of this story. The author has created a cast of characters, who are normal every day boys thrown into a dangerous adventure where they have to pit their wits against a couple of thugs. The boys, Jeff, Dan, his brother Mike and Jeff's cousin Stanley are extremely likable. The story is peppered with history from the Civil War, but I found it extremely interesting, as I'm not American and had not learnt a lot about that time period whilst at school. However, it does not slow the story down. In fact, the opposite is true. I found this book to be a fast paced roller coaster ride of action and adventure. I am now looking forward to reading the next book in the series, The Secret Graveyard.Jerrye Sumrall has written a fantastic mystery that kept me glued to the pages! I'm adding him to my ever expanding "favourite authors" list!I think this book is aimed at boys, but I highly recommend this book to children (boys and girls alike) between the ages of 9 and 12. However, I think that children as young as 7 may enjoy this as a bedtime story. - Lynn Worton