Andy and Terry try to solve the mystery of: What happened to Mr. Big Nose? After all, it's hard to turn in your next book when your publisher has vanished.

"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 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.

Having used their magic tree house to travel to India, where they must get a gift to help free the dog Teddy from a spell, Jack and Annie have adventures involving a tiger and other endangered jungle animals.

"When a new family moves into town, Kitty is excited to make another friend. But George, Kitty's new neighbor, is quiet and seems to have nothing in common with Kitty. When night approaches, Katsumi, a member of Kitty's cat crew, tells Kitty about a dog causing a commotion in the bakery. Kitty decides to use her catlike superpowers to investigate, and it turns out that George has his own superpowers, too! Together, they set off to track down the mischievous...

Joe conquers his fear of the strange creature moving into the house next door, as well as the treehouse in the creature's backyard.

"Build your own treehouses, swing sets, skate ramps, Ninja courses, and more! Kids and families of all ages are rediscovering the great outdoors, including their own backyards. It is more important than ever to be able to entertain our kids at home, teach them about nature, and give them a great time building, exercising, staying in shape, and working together. All of these actions help foster independence, confidence, and growth. In 'Backyard Playgrounds,'...

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.

The magic tree house takes Jack and Annie to Antarctica to search for the fourth secret of happiness for Merlin.

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.