For the past five hundred years, the Cahills have silently dominated the world. Their desperate hunt for the 39 Clues lies behind some of history’s biggest enigmas – the curse of the Hope diamond, the race to summit Mt. Everest, the wild life and death of Harry Houdini. And now – finally – the secrets are out. With an introduction by Rick Riordan, The 39 Clues: The Black Book of Buried Secrets reveals the shocking truth about history’s most notorious family.

In full, lush color, The 39 Clues: The Black Book of Buried Secrets lays bare each hidden fact, concealed strategy, top agent, lost founder, secret base and hushed-up scandal of the Clue hunt. This complete guide to the Cahills contains information on all five branches, including the notoriously elusive Madrigals. The must-know information includes:

- Full files on the enigmatic Man in Black.

- The true purpose of the Madrigal branch.

- The complete story of the fire that split the original Cahill family.

- The truth about the night Hope and Arthur Cahill died.

- Open access to the secrets of the Lucian, Ekaterina, Tomas and Janus branches.

It’s never too late to join the hunt – especially with The 39 Clues: The Black Book of Buried Secrets to provide complete access to the Cahill’s most deeply-buried secrets.