Mary Pope Osborne

Having used their magic tree house to travel to India, where they must get a gift to help free the dog Teddy from a spell, Jack and Annie have adventures involving a tiger and other endangered jungle animals.

The magic tree house transports Jack and Annie to the deck of the Titanic to find a mysterious gift that will free a small dog from a magic spell.

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.

Jack and his younger sister take a trip in their tree house back to ancient Egypt, where they help a queen's mummy continue her voyage to the Next Life.

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

"Join Jack and Annie as they as they meet one of the world's most famous illusionists - Harry Houdini!"--

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

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

As a thank-you from Merlin and Morgan, Jack and Annie are sent on what should be a vacation at a luxurious resort in Cozumel, Mexico, but is, by mistake, an adventure with ancient Mayans, instead.

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.