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 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.

During their vacation from school, English siblings Gerald, Jimmy, and Kathleen, with their friend, Mabel, discover an enchanted ring that makes wishes come true, but with unexpected consequences.

Eleven-year-old Princess Celie lives with her parents, the king and queen, and her brothers and sister at Castle Glower, which adds rooms or stairways or secret passageways most every Tuesday, and when the king and queen are ambushed while travelling, it is up to Celie--the castle's favorite--with her secret knowledge of its never-ending twists and turns, to protect their home and save their kingdom.

Charlie and his magically gifted friends and relatives work together to rescue Billy Raven, a young orphan, from a mysterious and dangerous couple who have adopted him.

Children come to visit a little girl who lives all alone inside a castle that is housed inside of a museum.

Mrs. Worm and Gloomsburg castle are taken over by ghosts.

When an ancient enchanter is released from the grounds of Bloor's Academy, threatening both of Charlie Bone's parents, the only way Charlie and his friends can defeat him is by finding the red king himself.

Eric and his friends learn that Zorfendorf Castle holds a secret which they must prevent from falling into the hands of Emperor Ko.

When the dangerous ancient wizard Arkwright escapes the dungeon and goes missing within the Castle, Princess Celie must find the wizard and save her family.