The end is near! Book 9 of the #1 NY Times Bestselling series.

The shadow of a man in black has followed fourteen-year-old Amy Cahill and her younger brother, Dan, on their worldwide search for 39 Clues that lead to a great power. Amy and Dan know the man in black has tried to kill them. They know he's a Madrigal, the most secretive and terrifying group hunting for the Clues. Amy and Dan have run hard and fast, but they can't escape the

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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,...

When Iranian-American Kamran Smith learns that his big brother, Darius, has been labelled a terrorist, he sets out to piece together the codes and clues that will save his brother's life and his country from a deadly terrorist attack.

It started with a kidnapping. A shadowy organization known only as the Vespers snatched seven members of the Cahill family and demanded a series of bizarre ransoms from around the world. Thirteen-year-old Dan Cahill and his older sister Amy began a global treasure hunt, determined to bring back whatever Vesper One needed, so long as it kept the hostages safe. But when they deliver the last ransom, Amy and Dan discover Vesper One's terrifying endgame....

As the race to find the 39 Clues builds to its explosive finish, Amy and Dan must explore an ancient culture and steal a Clue guarded by thousands of the world's best-trained soldiers. It's the most dangerous Clue search yet ... and it may mean the end for Amy and Dan.

When a mysterious letter written in code arrives at King's house for his human, Kayla, he follows the trail of the person who left it.

"The Vespers have crossed a line. Amy and Dan were devastated when the Vespers kidnapped seven Cahills around the world, holding them hostage until Amy and Dan delivered an impossible ransom. But at least the hostages were Cahills - members of the world's most powerful family, trained to face all odds. Now the Vespers have gone too far. They've kidnapped Atticus, an innocent 11 year old boy and Dan's only friend. Now Dan and Amy are in the struggle...

Amy and Dan cross the oceans on the trail of a famous aviator, but they find more than they're looking for as their enemies become more vicious, and the truths they discover become more crushing than ever.

Amy and Dan Cahill have their final confrontation with twisted billionaire J. Rutherford Pierce, a man whose power has no limits and is one step away from being elected president.

Shaken by a shocking loss, Amy and Dan flee to an exotic island in Indonesia to trace the footsteps of their most formidable ancestor yet: a military leader of mythic proportions.