I thought The Island of Dr. Libris was a great book. The author, Chris Grabenstein, did an awesome job putting together such a creatively imaginative book. Another thing I appreciated about this book was that it was so fun; I enjoyed reading it and couldn't wait to find out what happened next. I could tell a lot about the main character, Billy. He is curious, a great friend, and very trustworthy. A part in the book that I really liked was when Robin Hood and Hercules meet on the island after defeating a villain. Out of sport, Robin Hood challenges Hercules to a duel with nothing but a long staff to defend himself. You can probably guess how that went. I don't think there was anything I didn't like about this book. I would recommend this book to ages ten through fifteen, because I think that age group would enjoy this the most.