In their magic treehouse, Jack and Annie are again transported to King Arthur's realm, where invisible beings, giant ravens, and mistaken magic spells have a duke's castle in an uproar on Halloween night.

A classic faity tale romance tells the story of a drunken swordsman and a gentle giant who come to the aid of Westley, a handsome farm boy, and Buttercup, a princess in dire need of rescue from the evil schemers surrounding her.

Eight-year-old Jack and his younger sister Annie use the magic treehouse to travel back to the Middle Ages, where they explore a castle and are helped by a mysterious knight.

In 1940, during the Blitz, Katherine, Robbie and Amelie Bateson are sent north to a private school in Rookskill Castle in Scotland, a brooding place, haunted by dark magic from the past--but when some of their classmates disappear Katherine has to find out if the cause is hidden in the past or very much in the present.