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.

"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"--

Their magic tree house takes Jack and Annie back to a monastery in medieval Ireland, where they try to retrieve a lost book while being menaced by Viking raiders.

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.

After traveling through time in Shadow of Night, the second book in Deborah Harkness's enchanting series, historian and witch Diana Bishop and vampire scientist Matthew Clairmont return to the present to face new crises and old enemies. At Matthew's ancestral home at Sept-Tours, they reunite with the cast of characters from A Discovery of Witches--with one significant exception. But the real threat to their future has yet to be revealed, and when...

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

After falling for Kate, her unexpected death sends Jack back in time to the moment they first met. He soon learns that his actions have consequences when someone else close to him dies.

Raul Endymion, sentenced to orbit the quarantined world of Armaghast until his death, comforts himself by writing about Aenea, a mystical child he was appointed to guard who grew to be the woman he loved.

"An overworked book publicist with a perfectly planned future hits a snag when she falls in love with her temporary roommate...only to discover he lives seven years in the past, in this witty and wise new novel from the New York Times bestselling author of The Dead Romantics. Sometimes, the worst day of your life happens, and you have to figure out how to live after it. So Clementine forms a plan to keep her heart safe: work hard, find someone decent...

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.