The magic treehouse takes Jack and Annie back two thousand years to ancient China where they must find the original copy of an old legend before the Imperial Library is burned down by the evil Dragon King.

When eight-year-old Jack and his seven-year-old sister, Annie, join a group of nineteenth-century explorers aboard the H.M.S. Challenger, they learn about the ocean, solve the mystery of its fabled sea monster, and gain compassion for their fellow creatures.

When strange noises are heard in the tree house where their club meets, Claire and Kaz wonder if a rival club is causing problems in order to scare them away, or if they are coming from the ghosts of one of Kaz's departed ancestors.

Andy and Terry travel through time trying to save their treehouse from highly talented, angry ants and Inspector Bubblewrap the building inspector while rushing to meet their publisher's deadline.

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.

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

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.

"Andy and Terry are once again inviting readers to come hang out with them in their astonishing 39-story treehouse (it used to be 13 stories, then 26 stories, but they keep expanding). And this year they will have even more time to jump on the world's highest trampoline, toast marshmallows in an active volcano, swim in the chocolate waterfall, pet baby dinosaurs, and go head-to-trunk with the Trunkinator, since Terry has created the greatest invention...

The magic tree house carries Jack and Annie to New York City in 1938 on a mission to rescue the last unicorn.