Follow the Leader 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 messed up big-time. A Cahill from the past calling himself the Outcast has risen to challenge Ian with an impossible test. The Outcast has re-created four of history's greatest disasters and dared Ian to stop him. If Ian and his allies can't decipher the Outcast's hints in time, innocent people will die. Ian's only chance to beat the Outcast is to track down his former allies, Amy and Dan. But finding Amy and Dan will demand from Ian an impossible sacrifice . . .

Never turn your back on the Cahills . . . The most powerful family history has ever known returns with a vengeance in The 39 Clues: Doublecross! 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 and stop the tragedies before it's too late. Now, with one disaster behind them, siblings Dan and Amy Cahill and their friends have just days to discover what the Outcast's next move will be.Their frantic search seems to be pointing toward a terrifying air disaster, the explosion of the Hindenburg airship. But no one travels by airship anymore -- what do the Outcast's cryptic messages mean? The young Cahills must split up and take to the skies to try to find the answer . . . before their whole world comes crashing down.

The thrilling conclusion to 39 Clues Part VI: Doublecross. A Cahill family member from the past is bent on revenge! 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 fast, he will initiate a full-scale nuclear meltdown.But as Dan and Amy race around the world, they discover something horrifying. The Outcast's disasters are only a smoke screen to cover up his true plan, a diabolical revenge on the family that betrayed him. Soon Amy andDan will have to confront a hard truth: Sometimes the only way to save the world is to sacrifice everything you love.

The Cahill family has a secret. For five hundred years, they have guarded the 39 Clues - thirty-nine ingredients in a serum that transforms whomever takes it into the most powerful person on earth. Now the serum is missing. Dan Cahill and his older sister Amy have to get the serum back and stop who stole it...before it's game over. For everyone.

International bestseller David Baldacci pens the stunning conclusion to Cahills vs. Vespers! 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. The objects he demanded are vital pieces in a Vesper plot that will harm millions of innocent people. Now the two siblings and their friends are in an all-out sprint to stop Vesper One . . . before the whole world goes BOOM.

Minutes before she died Grace Cahill changed her will, leaving her descendants an impossible decision: "You have a choice - one million dollars or a clue." Grace is the last matriarch of the Cahills, the world's most powerful family. Everyone from Napoleon to Houdini is related to the Cahills, yet the source of the family power is lost. 39 Clues hidden around the world will reveal the family's secret, but no one has been able to assemble them. Now the clues race is on, and young Amy and Dan must decide what's important: hunting clues or uncovering what REALLY happened to their parents. The 39 Clues is Scholastic's groundbreaking new series, spanning 10 adrenaline-charged books, 355 trading cards, and an online game where readers play a part in the story and compete for over $100,000 in prizes. The 39 Clues books set the story, and the cards, website and game allow kids to participate in it. Kids visit the website - www.the39clues.com - and discover they are lost members of the Cahill family.Experience the complete adventure with Dan and Amy Cahill in this fantastic 10 book series collection - including the finale 39 Clues Book 10: Into the Gauntlet!