The 39 clues. Main series

Dan and Amy Cahill are given the choice of receiving a million dollars or uncovering the thirty-nine clues hidden around the world that will lead to the source of the family's power, but by taking on the clues, they end up in a dangerous race against their own family.

When Amy and Dan Cahill's quest to find the million dollars takes them to Japan, they must decide whether or not to enter into an alliance with their uncle, Alastair Oh, whose motives for helping them are extremely questionable.

A strange telegram lures Amy and Dan deep into Russia and away from the only trustworthy adult they know.

When Amy and Dan Cahill trace the footsteps of a formidable military leader from the Cahill bloodline, they uncover a devastating secret about the family that changes everything.

Throughout the hunt for the 39 Clues, Amy and Dan have encountered some of the darkest aspects of history... and had to deal with the role their family played. But are they ready for the truth? In this thrilling ninth installment, Amy and Dan hit the high seas as they follow the trail of some infamous ancestors to track down a long lost treasure. However, the real prize isn't hidden in a chest. It's the discovery of the Madrigals' most dangerous secret...

Defend the Clues

Fourteen-year-old Amy Cahill and her younger brother, Dan, thought they could return to their regular lives when they found the 39 Clues that safeguard their family's great power. But they were wrong. Powerful enemies—the Vespers—have been waiting in the shadows. And they'll stop at nothing to grab the Clues. Four powerhouse authors unite to expose the 500-year-old secret struggle between the Cahills and the Vespers. The

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