Mary Pope Osborne

Magically transported to southwest China to find the final object needed to break the spell on the wizard Merlin's beloved penguin, Jack and Annie take a side trip to the world's largest giant panda reserve.

Jack and Annie search for the fourth secret of greatness for Merlin the Magician in Mexico City at the 1970 World Cup Games where they hope to learn something new from soccer player great Pele.

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 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.

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.

Jack and Annie travel in their magic tree house to Elizabethan London, where they become actors in a production of A Midsummer Night's Dream and try to rescue a tame bear.

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

"Join Jack and Annie as they as they meet one of the world's most famous illusionists - Harry Houdini!"--

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

Travel to Ancient Greece with Jack and Annie as they meet Alexander the Great and help tame his wild stallion.