Monday with a Mad Genius (Merlin Missions, #10)

Jack and Annie are on a mission to save Merlin from his sorrows! The brother-and-sister team travel back in the magic tree house to the period known as the Renaissance. This time, Jack and Annie will need more than a research book and a magic wand. They'll need help from one of the greatest minds of all time. What will they learn from Leonardo da Vinci?

Did you know that there’s a Magic Tree House book for every kid?

Magic Tree Adventures with Jack and Annie, perfect for readers who are just beginning chapter books
Merlin More challenging adventures for the experienced reader
Super A longer and more dangerous adventure
Fact Nonfiction companions to your favorite Magic Tree House adventures