Meg and her classmates visit a medieval castle and become eyewitnesses to the theft of a priceless silver chalice. The reader is asked to solve the mystery before Meg, using clues found in the text and illustrations.
Creepella von Cacklefur helps Gorgo, the monster living in her moat, write a letter to the famous monster movie star Blobbina, and when they discover Blobbina has disappeared, they set out to find her.
The Strega-Borgia children, their mysterious new nanny, and a giant tarantula use magic and actual trips through the Internet to bring peace to their Scottish castle after the childrens' father is kidnapped.
The Aldens visit Ireland and stay in a beautiful castle that's now a hotel! But the caretaker seems very superstitious, and at night they see a mysterious figure who walks the halls carrying a lantern. Could it be one of the banshees of ancient legend? The Boxcar Children must discover the secret that Duncarraig castle is hiding!.
In 1558 while imprisoned in a remote castle, a young girl becomes involved in a series of events that leads to an underground labyrinth peopled by the last practitioners of druidic magic.