Rick Riordan
Rick Riordan only wrote the first 39 Clues book.
Peter Lerangis
He wrote a few as he wrote Percy Jackson series, and that Tres Navarre series, and the 39 clues and a beginning a book call Red Pyramid
There is not going to be a 12th 39 Clues book, but there is going to be a new 39 Clues series. The first book in the new series is called The Medusa Plot by Gordon Korman.
many authors ************** A different author for each book. Please specify which book you mean.
Rick Riordan
Patrick Carman wrote The Black Circle, the 5th book in the 1st 39 Clues series.
he wrote 18 books totally so far
The eighth book in The 39 clues series is 'The Emperor's Code.'
There are 6 clue cards in the first book of The 39 Clues series. Each card reveals an important clue or hint as part of the overarching mystery explored in the series.
The 39 Clues, Book 3: The Sword Thief was written by Peter Lerangis, a well-known author who has also written the Spy X series and the Drama Club series. Lerangis has also written the 7th book of The 39 Clues (The Viper's Nest) and the 3rd book of the second series, Cahills vs. Vespers (The Dead of Night).
book six in the 39 clues book is: In Too Deep, by Jude Watson