The explosive finale to Scholastic's mega-selling series. Throughout the hunt for the 39 Clues, Amy and Dan Cahill have uncovered history's greatest mysteries and their family's deadliest secrets. But are they ready to face the truth about the Cahills and the key to their unmatched power? After a whirlwind race that's taken them across five continents, Amy and Dan face the most the difficult challenge yet - a task no Cahill dared to imagine. When faced with a choice that could change the future of the world, can two kids succeed where 500 years worth of famous ancestors failed?

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.

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.

ATTENTION! Amy and Dan Cahill have been located once again, this time in the company of the notoriously unreliable Alistair Oh. Could they have been foolish enough to make an alliance? Spies report that Amy and Dan seem to be tracking the life of one of the most powerful fighters the world has ever known. If this fearsome warrior was a Cahill, his secrets are sure to be well-guarded . . . and the price to uncover them just might be lethal.

39 clues to unscramble. One fabulous prize to win. It's a riddle, a book and a game to play. Are YOU up to the challenge? Written by celebrated author Rick Riordan, this interactive challenge takes books to a place they've never been before.