A clue found in Japan has Amy and Dan jetting off to Egypt to find out just 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?

"A cruise ship loses power in the North Atlantic. A satellite launches in the South Pacific. Professor Malcolm Clare--celebrated aviator, entrepreneur, and aerospace engineer--disappears from Stanford University and wakes up aboard an unknown jet, minutes before the aircraft plunges into the high seas. An extortionist code-named 'Viking' has seized control of a private warfare technology, pitting a U.S. defense corporation against terrorist conspirators...

Using their code-breaking skills, four middle-schoolers solve the mystery of the eccentric man who draws stick figures on his second-floor bedroom window.

After seven members of their family are kidnapped by an organization called the Vespers, Dan and Amy Cahill must race against time to track down an ancient map to pay as ransom to bring the hostages home.

Chronicles the first Vesper attack on Jan van Eyck's altarpiece at Ghent in the 1600s, then jumps to WWII and young Grace Cahill's desperate bid to save the masterwork from the Nazis.

Cahills are being kidnapped by a shadowy group known only as the Vespers. Now Amy and Dan have only days to fulfill a bizarre ransom request or their captured friends will start dying. Amy and Dan don't know what the Vespers want or how to stop them. Only one thing is clear. The Vespers are playing to win, and if they get their hands on the Clues ... the world will be their next hostage.

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 dangerous race against their own family members.

Sarah and Aidan begin to decipher a mysterious document that refers to the origins of Peter Pan and are suddenly pursued by a being that can take any form and will stop at nothing to get what it wants from them.