Le t the hunt begin. During the reading of their grandmother's will, Dan and Amy Cahill learn that the secrets to their family's power is hidden in the form of 39 Clues around the world. At the reading of their grandmother's will, Dan and Amy Cahill are given the choice of receiving a million dollars or uncovering the 39 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...

It's no longer a game. The body count is rising. Shaken by recent events, Amy and Dan flee to a distant 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 something so devastating it changes everything...

"Are some secrets better left buried? As Amy and Dan track the next clue to a remote corner of the world, they make shocking discoveries about the source of the Cahills' power and the mystery of their parents' deaths. And as the threat of the mysterious Madrigals grows real, one of the clue-hunters makes the ultimate sacrifice. Amy and Dan have to decide how much they're willing to risk, and what they are fighting for. Can they avenge their parents...

Guardians of the 39 Clues, Dan Cahill and his sister Amy discover that the serum is missing and must race against time to get it back before catastrophe strikes.

Amy and Dan Cahill 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 and, even more shockingly, the true identity of the mysterious man in black.

When seven members of their family were kidnapped, thirteen-year-old Dan Cahill and his older sister, Amy, got ready for the fight of their lives. But their enemy, a terrifying group known as the Vespers, remained frustratingly elusive. They stay in the shadows, picking off Cahills one by one. And now the Vespers have landed their most serious blow yet ? A blow that strikes at the very heart of the Cahill family. Because Amy and Dan discover that...

"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....

When seven members of the Cahill family are kidnapped, thirteen-year-old Dan Cahill and his older sister Amy discover it is a group calling themselves the "Vespers." Both children discover there is a spy among them giving the Vespers information. If they don't put a stop to the information leak, family members will die.

The race to find the 39 Clues leads fourteen year old Amy Cahill and her younger brother to Indonesia and they see a woman die. Now they're wanted by the Indonesian police and they are trapped on an island with a man who knows too much about their parents death.

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