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 39 Clues
On April 26, 2014, at the New Hampshire Worlds Collide event, Scholastic announced a fourth series titled "Doublecross". The series began with Jude Watson's "Mission Titanic" (2015), followed by C. Alexander London's "Mission Hindenburg" (2015) and Jenny Goebel's "Mission Hurricane" (2016). The series concludes with Sarwat Chadda's "Mission Atomic" published on June 28, 2016. Amy, Dan, and their allies try to thwart the Outcast's plans of mass destruction.