Mary Pope Osborne

Jack and Annie travel in their magic tree house to the land of the mystical selkies to seek a magical sword for Merlin.

Jack and Annie go on a series of missions in order to help the wizard Merlin, traveling around King Arthur's realm and to such places as Venice, Baghdad, Paris, and New York City.

Jack and Annie travel to Vienna, Austria, in 1762, where they meet the young Wolfgang Amadeus Mozart and his sister and help save the budding genius's life.

Their magic tree house takes Annie and Jack to Pompeii just as Vesuvius is about to erupt, and they must find a Roman scroll before everything is covered with burning ash.

Blizzard of the blue moon: Jack and Annie go back in time to New York City, 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. To stop the blizzard, Jack and Annie must save the unicorn made famous in the Cloister's medieval tapestries. But will that be enough to help a city that faces so many troubles? Dragon of the red dawn: When Merlin is weighed down by sorrows,...

Their magic tree house takes Jack and Annie back to the Wild West, where they experience excitement and danger and try to solve a riddle.

La casa del árbol lleva a Annie y Jack a California, en 1806, en el momento justo del famoso terremoto de San Francisco. ¿Podrán Annie y Jack encontrar el último escrito para que Morgana salve al reino de Camelot? ¿Lo lograrán antes de que San Francisco quede en ruinas? 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.

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.

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.

Monday with a mad genius: Jack and Annie travel 500 years back in time to Florence, Italy, and spend a day helping Leonardo da Vinci in the hope of learning another secret of happiness. Dark day in the deep sea: 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...