The #1 bestselling chapter book series of all time celebrates 25 years with new covers and a new, easy-to-use numbering system!

Jack and Annie are off on another mythical mission at the request of Merlin the magician. Luckily, they have a young sorcerer, Teddy, to help them. From underwater caves to a Spider Queen, from mystical selkies to a magical sword, this is a Magic Tree House adventure kids wont want to miss!

Formerly numbered as Magic Tree House #31, the title of this book is now Magic Tree House Merlin Mission #3:Summer of the Sea Serpent.

Did you know that theres a Magic Tree House book for every kid?

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