One False Note
One False Note is the second book in "The 39 Clues" series. It is written by Gordan Korman, and was published by Scholastic on December 2, 2008. Following the events of "The Maze of Bones", the protagonists Amy and Dan Cahill learn about Mozart and travel to Vienna, Austria to search for the second clue in the 39 Clues competition. "One False Note" entered the Children's Books New York Times Best Seller list at number one on December 21, 2008 and stayed on the list for children's chapter books for 12 weeks.
The Medusa Plot
The Medusa Plot is the first book in the "" series. The book was written by Gordan Korman and released on August 30, 2011. The story picks up two years after the original series "The 39 Clues" and is about the Cahills' attempt to save members of their family that have been kidnapped by following the instructions given by Vesper One.