Mary Pope Osborne

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.

Jack and Annie are transported by their magic tree house to the time of the Civil War where they meet Clara Barton.

Eight-year-old Jack, his seven-year-old sister, Annie, and Peanut the mouse ride in a tree house to the Amazon rain forests, where they encounter giant ants, flesh-eating piranhas, hungry crocodiles, and wild jaguars.

It's a treasure trove of trouble! Jack and Annie are in for a high-seas adventure when the magic tree house whisks them back to the days of deserted islands, secret maps--and ruthless pirates! Will they discover a buried treasure? Or will they be forced to walk the plank? The magic treehouse whisks Jack and Annie back to the days of deserted islands, secret maps, hidden gold, and nasty pirates.

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

Their magic tree house takes Jack and Annie to the Arctic, where a polar bear leads them onto very thin ice.

The magic tree house whisks Jack and Annie away to Australia where they must save some animals from a wildfire.

Their magic tree house takes Jack and Annie back to a monastery in medieval Ireland, where they try to retrieve a lost book while being menaced by Viking raiders.

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.