Wow! What a cool visual mystery! It's kind of like I Spy meets Sherlock Holmes. The only reason I didn't give it five stars is because there were a few times where it was a little too hard, in my opinion.
That being said, this is the PERFECT book for any older kids 10 and up who LOVE solving mysteries, deciphering notes, putting pieces together, and looking for parallels. I love how this book made you use your brain. There are clues and answers in the back (both very helpful... I had to look up the answers sometimes) and lots of fun, challenging puzzles. And when you get them right, you feel super smart!