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.

Meg Murry and her friends become involved with unearthly strangers and a search for Meg's father, who has disappeared while engaged in secret work for the government.

Joe receives a magic book for his birthhday present from his uncle. Joe, Fred and Sam are transported to a time when evil knights, fire-breathing dragons and vile-smelling giants roamed the land.

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...

"Regan Fitz and Elliot Mason have been enemies since they started training to become Glitchers--people who travel through time to preserve important historical events. But everything changes when they find a letter from Regan's future self, warning them about an impending disaster that threatens them and everyone they know. Will they be able to set aside their past in order to save the future?"--

When Merlin is weighed down by sorrows, Jack and Annie travel back to feudal Japan to learn one of the four secrets of happiness.

Jack and Annie travel back to Victorian London when Merlin asks them to use their magic to inspire Charles Dickens to write "A Christmas Carol."

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.

While on a field trip to New York's Museum of Natural History, Joe, Sam, and Fred travel one hundred years into the future, where they encounter robots, anti-gravity disks, and their own grandchildren.

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.