"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"--

At first it seems that Peter Hatcher's summer vacation is going to be a scene from his worst nightmare. Peter's parents have decided to spend three weeks in Maine sharing a house with Cootie Queen Sheila Tubman and the rest of her family. To make matters worse, Peter's younger brother, Fudge, the five-year-old human dynamo, has decided to marry Sheila! But things begin to look up once Peter discovers that Maine is full of surprises, and his best friend...

Guided by a magic rhyme, Jack and Annie travel to ancient Baghdad on a mission to help the Caliph disseminate wisdom to the world.

Third-grader Clementine's school field trip to Plimoth Plantation leads to all kind of discoveries, from fourth grade eating rules to the source of the stink on the bus.

Jack and Annie travel in their magic tree house back to a Hawaiian island of long ago where they make friends, learn how to surf, and encounter a tsunami.

When Bear decides to give the moon a birthday present, he climbs a mountain to get close enough to ask what day is the moon's birthday.

"Jack and Annie travel back in time to 1925 Nome, Alaska, where they meet Balto, the famous sled dog, and help save the town from illness"--

When Jack and Annie travel back to the Kansas prairie in search of "something to learn," they gain an understanding of how hard life was for pioneers and they experience the terror of a tornado.

"The magic tree house takes Jack and Annie to Africa where they meet up with wonderful wild animals, a very hungry warrior, and where they even solve a riddle."--

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