"Andy and Terry live in a 39-story treehouse, with the world's highet trampoline, a chocolate waterfall, a baby-dinosaur petting zoo, an active(non-erupting) volcano, a boxing elephant called The Trunkinator, the world's scariest roller coaster, and a level that is so new and so secret that Terry hasn't even finished it yet!"--P. [4] of cover.

Andy and Terry live in a 26-story treehouse. (It used to be 13 stories, but they've expanded.) It has a bumper car rink, a skate ramp, an antigravity chamber, an ice cream parlor with 78 flavors, and the Maze of Doom—a maze so complicated that nobody who has gone in has ever come out again. Well, not yet, anyway.
This time, the two friends have a whole week to finish their next book, and Andy even knows what it should be about—the

...

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.

The magic tree house takes Jack and his sister Annie to the Great Plains where they learn about the life of the Lakota Indians.

"Jack and Annie are magically transported to mid-1800's Thebes where they are saved from a dangerous accident by Florence Nightingale!"--

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.

"Nine long months after being shut out of the pillow fort network for good, Maggie and Abby finally have a whole new mission to focus on--and this one starts with a return to the infamous Camp Cantaloupe. Abby needs this trip after a year of big, BIG changes back at home. But Abby knows that Maggie will never relax until they've solved the lingering puzzle left over from last summer: the mystery of the trap door in Camp Cantaloupe's historic Shipwreck...

"Jack and Annie are about to meet the fiercest warriors of all--the soldiers of the ancient Roman legion! When the magic tree house whisks them back to a ROman army camp, they learn their mission: Be like warriors. That is easier said than done--Roman soldiers are the best fighters in the world! When Jack and Annie find themselves in the wrong place at the wrong time, they're in big trouble. Who will save Jack and Annie?"--Page [2] of cover.

"The magic tree house whisks Jack and Annie away to South America, where they must climb Machu Picchu to save a baby llama."--

"When a mysterious note invites them to Camelot, Jack and Annie travel in the magic tree house to the magical kingdom where they must find a lost dragon"--