The Emperor's Code is the eighth book in The 39 Clues series. This book is written by Gordon Korman. On March 2, 2010 the cover was revealed to show a red mask with codes printed in certain areas over a purple background. After this release, readers were asked to find three out of the four codes printed on the mask, and, if they were successful, 39 Clues fans could read an excerpt from The Emperor's Code.
Through out the book, there are certain letters and phrases that are circled. Page Messages Throughout the book, certain words, or even parts of words are circled.
If you put the words together, they spell:
Madrigals are behind everything. They lay out the path the others will walk. The end is coming. There is also a code on the mask that can be decoded on the copyright page. It says TENZING KNEW TOO.