When thirteen-year-olds Jonah and Chip, who are both adopted, learn they were discovered on a plane that appeared out of nowhere, full of babies with no adults on board, they realize that they have uncovered a mystery involving time travel and two opposing forces, each trying to repair the fabric of time.

"It was a dark and stormy night; Meg Murry, her small brother Charles Wallace, and her mother were in the kitchen for a midnight snack when they were upset by the arrival of a most disturbing stranger. 'Wild nights are my glory,' the unearthly stranger told them. 'I just got caught in a downdraft and blown off course. Let me sit down for a moment, and then I'll be on my way. Speaking of ways, by the way, there is such a thing as a tesseract.' A tesseract...

"Cassie Andrews works in a New York City bookshop, shelving books, making coffee for customers, and living an unassuming, ordinary life. Until the day one of her favorite customers--a lonely yet charming old man--dies right in front of her. Cassie is devastated. She always loved his stories, and now she has nothing to remember him by. Nothing but the last book he was reading. But this is no ordinary book... It is the Book of Doors. Inscribed with...

When Jack and Annie travel back to the Kansas prairie in search of "something to learn," they gain an understanding of how hard life was for pioneers and they experience the terror of a tornado.

After his girlfriend Holly is fatally shot during a violent struggle, nineteen-year-old Jackson uses his supernatural abilities and travels back in time two years, where he falls in love with Holly all over again, learns that his father is a spy, and discovers powerful enemies of time who will stop at nothing to recruit him for their own purposes.

The magic tree house takes Jack and Annie back in time to feudal Japan where the siblings learn about the ways of the Ninja.

"One brilliant June day when Mia Jacob can no longer see a way to survive, the power of words saves her. The Scarlet Letter was written almost two hundred years earlier, but it seems to tell the story of Mia's mother, Ivy, and their life inside the Community--an oppressive cult in western Massachusetts where contact with the outside world is forbidden, and books are considered evil. But how could this be? How could Nathaniel Hawthorne have so perfectly...

Greedy Llama travels back in time to eat his marvelous birthday donut a second time, but a Baby Llama follows him to the present, and soon his house is a chaos of cave llamas, barbarian bunnies, and Viking pigs.

The magic treehouse whisks Jack and Annie back to the days of deserted islands, secret maps, hidden gold, and nasty pirates.

The magic treehouse 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.