The number one best-selling book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system!

Jack and Annie arrive on the one continent they haven’t visited before: Antarctica! What can they hope to learn about happiness in such a barren place? Only the penguins know for sure...Jack and Annie are about to find out!

Formerly numbered as Magic Tree House Number 40, the title of this book is now Magic Tree House Merlin Mission Number 12: Eve of the Emperor Penguin.

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

• Magic Tree House: Adventures with Jack and Annie, perfect for listeners who are just beginning to listen to audiobooks
• Merlin Missions: More challenging adventures for the experienced listener
• Super Edition: A longer and more dangerous adventure
• Fact Trackers: Nonfiction companions to your favorite Magic Tree House adventures