An escalating race to find the 39 Clues finds Amy and Dan pursuing a Clue guarded by thousands of the world's best-trained soldiers, an effort that separates them in explosively dangerous ways.

Tensions run high in the explosive 8th book of 39 Clues, the #1 New York Times bestselling series. One belief has sustained fourteen-year-old Amy Cahill and her younger brother, Dan, on their hunt for the 39 Clues: They are the good guys. But then a shocking discovery about their parents shatters everything Amy and Dan think they know, dividing the two siblings for the first time ever. When Dan disappears in a country of more than a billion people, Amy has to make a terrible choice - find the next Clue . . . or find her younger brother.

The most dangerous secret in Amy and Dan's past is unveiled in Book 7 of the #1 New York Times best-selling series. It's no longer a game. The body count is rising. Shaken by recent events, Amy and Dan flee to an exotic land and trace the footsteps of their most formidable ancestor yet: a military leader of mythic proportions. Yet just as the siblings begin to master the art of ancient warfare, they confront a dangerous enemy that can't be felled with a sword: the truth. With the stakes higher than ever, Amy and Dan uncover a devastating secret that changes everything.

As they continue their search for the 39 Clues in China, fourteen-year-old Amy is faced with a terrible dilemma when her eleven-year-old brother Dan suddenly disappears--keep on searching for the next Clue or try to find her brother.

Amy and Dan dodge the shadow of a man in black as they search for the 39 clues.

A guide to the characters and situations in "The 39 Clues" outlines the Cahills' secrets, including hidden facts, strategies, agents, lost founders, secret bases, and scandals, as well as information about all branches of the family.