The magic treehouse takes Jack and Annie to a moon base in the future where they continue to search for the fourth thing they need to free their friend Morgan from the magician's spell.

Books 9–16 of the New York Times bestselling Magic Tree House series!
These eight titles are the perfect gift for a Magic Tree House fan or any child who loves a good adventure. Parents, teachers, and librarians hail the chapter-book series as a tool to promote reading, as even the most reluctant readers want to know where the Magic Tree House will take the brother-and-sister team next.
 
In books 9–12,...

Eight-year-old Jack and his younger sister Annie find a magic treehouse, which whisks them back to an ancient time zone where they see live dinosaurs.

The magic tree house transports Jack and Annie to the deck of the Titanic to find the mysterious gift that will free a small dog from a magic spell.

Their magic tree house takes Jack and Annie back to a monastery in medieval Ireland, where they try to retrieve a lost book while being menaced by Viking raiders.

When Merlin is weighed down by sorrows, Jack and Annie travel back to feudal Japan to learn one of the four secrets of happiness.

Jack and Annie are transported by their magic tree house to the time of the Civil War where they meet Clara Barton.