The magic tree house carries Jack and Annie to New York City in 1938 on a mission to rescue a magical unicorn from New York City. They arrive during one of the darkest periods in the city's history--the Great Depression. Even worse, the city is in the grip of a terrible snowstorm. Where will Jack and Annie ever find a unicorn in the city? And who are the mysterious people following them? Includes instructions to make a snow globe.

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.

Merlin the magician will not eat or sleep or speak to anyone. The enchantress Morgan asks young Jack and Annie of Frog Creek, Pennsylvania for help. Jack and Annie know they have to search for one of the four secrets of happiness to help Merlin the magician find joy in his life again. And so they head off in the magic tree house for Florence, Italy, in the early 1500s, then to a misty island in the middle of nowhere, then to the continent of Antarctica....

Who wouldn't want to live in a treehouse? Especially a 13-story treehouse that has a bowling alley, a see-through swimming pool, a tank full of sharks, a library full of comics, a secret underground laboratory, a games room, self-making beds, vines you can swing on, a vegetable vaporiser and a marshmallow machine that follows you around and automatically shoots your favourite flavoured marshmallows into your mouth whenever it discerns you're hungry....

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

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Andy and Terry live in a 26-storey treehouse. It has a bumper car rink, a skate ramp, an antigravity chamber, an ice cream parlor with 78 flavors, and the Maze of Doom. This time, the two friends have a whole week to finish their next book, and Andy even knows what it should be about; the story of how he and Terry first met. But, life is never boring in the treehouse, and emergency shark operations, giant storms, and wooden pirate heads are just the...

As a thank-you from Merlin and Morgan, Jack and Annie are sent on what should be a vacation at a luxurious resort in Cozumel, Mexico, but is, by mistake, an adventure with ancient Mayans, instead.

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.