As her mother prepares to be a contestant on the 1980s television game show, "The $20,000 Pyramid, " a twelve-year-old New York City girl tries to make sense of a series of mysterious notes received from an anonymous source that seems to defy the laws of time and space.

After returning the missing children from history to their original time periods, thirteen-year-old Jonah must save time itself when aviator Charles Lindbergh mysteriously appears and kidnaps Jonah's sister.

Artemis's mother has contracted a deadly disease -- and the only cure lies in the brain fluid of African lemurs. Unfortunately, Artemis himself was responsible for making the lemurs extinct five years ago. Now he must enlist the aid of his fairy friends to travel back in time and save them. Not only that, but he must face his deadliest foe yet...his younger self.

Tess de Sousa leaves Miss Ackerbee's orphanage to live with her new guardian in Roedeer Lodge, taking with her a fondness for scientific experimentation, a pet tarantula named Violet, and a device that allows her to travel to parallel universes.

The magic tree house whisks Jack and Annie away to Australia where they must save some animals from a wildfire.

While spending the summer in a house by the sea, four cousins, Roger, Ann, Eliza, and Jack, discover a bank of wild thyme whose magic propels them on a series of adventures back and forth through time.

Kate, Michael, and Emma have passed from one orphanage to another in the ten years since their parents disappeared to protect them, but now they learn that they have special powers, a prophesied quest to find a magical book, and a fearsome enemy.

"When something crucial goes missing, eleven-year-old Olive and her friends must decide how to get it back--put their faith in a strange and dangerous magic, their odd new neighbors, or someone more uncertain and terrifying than both"--

"Annie, Edward, and their young daughter, Rose, live in a cramped apartment. One night, without warning, they find a beautiful terrace hidden in their closet. It wasn't there before, and it seems to only appear when their friend Stephanie visits. A city dweller's dream come true! But every extra bit of space has a hidden cost, and the terrace sets off a seismic chain of events, forever changing the shape of their tiny home, and the shape of the world"--...

After mastering the ability to walk between dimensions, sixteen-year-old Joey Harker and his fellow InterWorld freedom fighters embark on a mission to maintain peace between the rival powers of magic and science who seek to control all worlds.