Scholar Jules Addison and scavenger Amelia Radcliffe join forces to unravel secrets of a long-extinct civilization, only to discover something that could spell the end of the human race.

657 days ago Meg's British father left their home in France to fight the Nazis, leaving some codes in a jar for her to decipher, and Meg and her French mother moved to the Perche, a region in France near Normandy known for its forests; now Meg watches the German soldiers in town, and sometimes carries messages for the French resistance--but suddenly things have gotten much more dangerous: there is a wounded British officer hiding in her grandmother's...

Told in multiple voices, fifteen-year-old Jamaican Louisa Adair uncovers an Enigma machine in the small Scottish village where she cares for an elderly German woman, and helps solve a puzzle that could turn the tide of World War II.

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 best-selling series returns with an even deadlier challenge as Amy and Dan's race to save the hostages reaches its thrilling conclusion as a new enemy is revealed to be searching for The 39 Clues. Final episode written by an internationally acclaimed, best-selling author.

A clue found in Book 3 sends Amy and Dan jetting off to Egypt to find out what's behind the fierce rivalry between the Tomas and Ekaterina branches of the Cahill family. Was a clue stolen from the Tomas branch? Where is it now? And, most important, can Amy and Dan get their hands on it before their rivals do?

"Elusive art thief Lars Heinrich returns to New York City looking to settle a score. Super sleuth seventh-grader Edmund Xavier Lonrrot will need not only his photographic mind and artistic talents, but any skill he possesses with cracking codes as a string of the city's historical monuments become potential clues in what could become one of the greatest heists in history"--

After twelve-year-old Addison Cooke's uncle unearths ancient Incan secrets in Peru, he is kidnapped by a shadowy organization intent on stealing the treasure unless Addison and his friends can decipher the clues first.

In the first 39 Clues book, Amy and Dan Cahill discovered that they're part of one of the most powerful families in human history. Passing up a pile of hush money, the siblings set out to uncover the 39 clues which would reveal the source of their family's awesome power. Here, in the sixth book, the siblings continue to uncover one clue at a time, encountering Cahill family branches and the mysterious Madrigals in the process. Amy and Dan cross the...

Code-breaking genius William Wenton returns to the Institute for Post-Human Research in hopes of discovering why the intelligent metal luridium in his body seems to be causing seizures, but while there he encounters secrets, increased security, and threats from an enemy he thought was frozen in the basement.