Mary Pope Osborne

Eight-year-old Jack and his younger sister Annie find a magic tree house, which whisks them back to an ancient time zone where they see live dinosaurs.

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.

Guided by a magic rhyme, Jack and Annie travel to ancient Baghdad on a mission to help the Caliph disseminate wisdom to the world.

The magic tree house takes Jack and Annie to Africa where they meet up with wonderful wild animals and a very hungry warrior.

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.

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

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

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

Their magic tree house takes Jack and Annie deep into the sea, where they meet up with dolphins, sharks and octopi as they search for the answer to an ancient riddle.

The magic tree house whisks Jack and Annie to India during the Mogul Empire in the 1600s to search for an emerald needed to break a magic spell.