A tree house that travels through time? Not possible, says Jack. But he has to admit--when he and his younger sister, Annie, start running into dinosaurs--that they're not in Frog Creek, Pennsylvania, anymore. Eight-year-old Jack and his younger sister Annie find a magic treehouse, which whisks them back to an ancient time zone where they see live dinosaurs.

The magic tree house takes Jack and Annie to a moon base in the future where they continue to search for the fourth thing they need to free their friend Morgan from the magician's spell.

On Christmas Eve, Jack and Annie's tree house transports them to King Arthur's castle at Camelot, where they undertake a quest to the castle of the Otherworld.

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

#18 The magic tree house takes Jack and his sister Annie to the Great Plains, where they learn about the life of the Lakota Indians.

The magic tree house transports Jack and Annie on a mission to the Ice Age where they encounter Cro-Magnons, cave bears, sabertooth tigers, and woolly mammoths.

"Beware of Vikings!" warns Morgan. Then Jack and Annie are whisked back to ancient Ireland. They land on a cliff on a misty island. How will they find the story they are looking for? It will take a Viking invasion, the help of a jolly monk, and a lot of courage for Jack and Annie to succeed.

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

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 travel in their magic tree house to the land of the mustical selkies to seek a magical sword for Merlin.