Mary Pope Osborne

On Christmas Eve, Jack and Annie's tree house transports them to King Arthur's castle at Camelot, where they undertake a quest to the castle of the Otherworld.

The magic treehouse takes Jack and Annie to a moon base in the future where they continue to search for the fourth thing they need to free their friend Morgan from the magician's spell.

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

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

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

While on a mission to prove to Merlin that they can use magic wisely, Jack and Annie travel to seventeenth-century Venice, Italy, to save the city from disaster. Merlin has asked Jack and Annie to help on another Merlin Mission. This time they head back into history to Venice, Italy, in the 1700s. With the help of some new friends, a research book, and a mysterious rhyme from Merlin, the heroes will save the beautiful city from a flood! Yet another...

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.

Jack and Annie travel back to nineteenth-century Ireland to inspire a young Augusta Gregory to share her love of Irish legends and folktales with the world.

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.

The magic tree house takes Jack and Annie to San Francisco in 1906, in time for them to experience one of the biggest earthquakes the United States had ever known.