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.

When a second-rate cage fighter, Luke Wright, is tormented by the Russian Mafia and wanders the streets of New York, he witnesses a young Chinese girl, Mei, being pursued by the same mafia who want her for a priceless numerical code that they would kill for.

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

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,...

Shows how symbols are used for whole words and letters. Also includes methods for making invisible ink. Examples of cryptic messages from Caesar's day to the discovery of the Rosetta Stone are also given.

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 Bertie the badger visits his grandfather at a retirement home for magicians, he learns that his grandfather's rabbit, Enigma, has disappeared along with everyone's magical things, and the reader is invited to help break a code to find the items hidden throughout the book. Includes a built-in decoder.

From the ingenious ciphers of Italian princes to the spy books of the Civil War to the advanced techniques of the CIA, codes and code breaking have played important roles throughout history.

Jax and Ethan must decode an ancient Greek cipher to uncover the location of two magical urns before the urns are used to remove all faith and love from the world.