What would happen if you discovered that your family was one of the most powerful in human history? What if you were told that the source of the family's power was hidden around the world, in the form of 39 clues? What if you were given a choice - take a million dollars and walk away ... or get the first clue? If you're Amy and Dan Cahill, you take the clue - and begin a very dangerous race.

A million dollars, or a clue? Police report a break-in at an elite hotel, and the suspects sound suspiciously like Amy and Dan. There's a car and speedboat chase and an angry mob! When there's a clue on the line, anything can happen.

A clue takes Amy and Dan Cahill to Egypt, where they investigate the origins of the rivalry between the Tomas and Ekaterina branches of their family and try to figure out if they can trust a message from their dead grandmother Grace.

A mysterious telegram sends Amy and Dan Cahill off to Russia, where they search for a treasure stolen by the Nazis, the truth about the end of the Romanov dynasty, and information about the death of their parents.

Orphans Amy and Dan Cahill, continuing their worldwide quest to track down the thirty-nine clues that will reveal the secret of the Cahill family's power, follow a link to one of the planet's strongest fighters, and have a run-in with the unreliable Alistair.

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.

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,...

Amy and Dan, wanted by the Indonesian police and stranded on an island with a tropical storm on the way, are about to discover a terrible truth about their branch of the Cahill family.

Thirteen-year-old Dan Cahill and his older sister, Amy, thought the search for the thirty-nine clues leading to the source of their family's power was over, but when Cahills are kidnapped by the Vespers, Amy and Dan find themselves with only a few days to fulfill a bizarre ransom request before their friends start dying.