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

Seventeen-year-old Zelie, her older brother Tzain, and rogue princess Amari fight to restore magic to the land and activate a new generation of magi, but they are ruthlessly pursued by the crown prince, who believes the return of magic will mean the end of the monarchy.

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

Lara Jean keeps her love letters in a hatbox her mother gave her. They aren't love letters that anyone else wrote for her, these are the ones she's written. One for every boy she's ever loved--five in all. When she writes, she can pour out her heart and soul and say all the things she would never say in real life, because her letters are for her eyes only. Until the day her secret letters are mailed, and suddenly Lara Jean's love life goes from imaginary...

In 1940, during the Blitz, Kat Bateson is sent to a school in a Scottish castle that is said to be haunted by dark magic from the past, but when some of her classmates disappear, she wonders if the magic exists very much in the present.

Twelve-year-old twins Nick and Eryn and their robot stepsiblings, Jackson and Ava, try to save humanity from killer robots.

A clue takes Amy and Dan Cahill to Egypt, where they investigate the origins of the rivalry between the Tomas and Ekaterina branches of their family and try to figure out if they can trust a message from their dead grandmother Grace.

The magic tree house whisks Jack and Annie to Washington D.C. in the 1860s where they meet Abraham Lincoln and collect a feather that will help break a magic spell.

The Aldens realize the food their dog, Watch, is eating in a commercial and enjoying is not the same as what is being sold in stores, and must decide whether they should continue to allow him to work for the dishonest company.

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.