Series The 39 Clues: Doublecross

CHECKMATEThirteen-year-old Dan Cahill and his older sister, Amy, are running out of time. An exiled Cahill known as the Outcast has already re-created three of history's worst disasters, and he's saved the worst for last. If Dan and Amy can't find and stop the Outcast fas...

Thirteen-year-old Dan Cahill and his older sister, Amy, know that a disaster is about to strike the world. They know they are the only ones who can stop it, and they know they may already be too late. The person behind the disaster is their own relative, a man who calls himself t...

The Cahills are the world's most powerful family, but their strength is being tested. A sinister man calling himself The Outcast has targeted the family and set them an impossible test. He's recreating four of history's worst disasters and challenging the young Cahills to find an...

At only seventeen years old, Ian Kabra is head of the Cahills, the most powerful family in the world. He has presidents on speed dial, generals at his beck and call. Ian knows he's an ideal leader and the only man enough for the job. There's just one small problem: He's already m...