Mary Pope Osborne

The magic treehouse whisks Jack and Annie back to the days of deserted islands, secret maps, hidden gold, and nasty pirates.

Jack and his younger sister take a trip in their tree house back to ancient Egypt. They find themselves in a pyramid's maze and need to find their way out before they become mummies themselves.

Using their magic tree house, Jack and Annie travel back to the time of the American Revolution and help General George Washington during his famous crossing of the Delaware River.

The magic tree house takes Jack and Annie to Antarctica to search for the fourth secret of happiness for Merlin.

Jack and Annie travel to a monastery in the Swiss Alps where, with the help of St. Bernard dogs and magic, they seek the second of four special objects necessary to break the spell on the wizard Merlin's beloved penguin, Penny.

Jack and Annie visit the Paris World's Fair of 1889 in an effort to protect four scientific pioneers from an evil sorcerer.

"The magic tree house has taken Jack and Annie back in time to England in 1944. England is fighting for its life in World War II. Before long, Jack and Annie find themselves parachuting into Normandy, France, behind enemy lines. The date is June 5. Will the brave brother and sister team be able to make a difference during one of the darkest times in history?"--

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...