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. If the serum got into the wrong hands, the disaster would rock the world. So certain Cahills have always made it their mission to keep the serum safe, buried, locked away. Until now. Thirteen-year-old Dan Cahill and his older sister, Amy, are the latest guardians of the Clues. They think they've done everything right, but a tiny mistake leads to catastrophe.

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.

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 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.

Calling all Cahills! Announcing a 39 Clues Superspecial adventure - the gang is back, and called to investigate one of their own: Sinead Starling.

For 500 years, the Cahills have been the most powerful family in the world. For 500 years, they've protected the source of their power - the 39 Clues. And for 500 years, they've kept their secrets silent. Until now. This extraordinary stand-alone novel cracks open the Cahill vault to tell the story of the most coveted piece of artwork in the world, a masterpiece that has been the target of seven separate theft attempts: Jan van Eyck’s altarpiece at Ghent.

Aidan and Meg Falconer are their parents' only hope. The Falconers are facing life in prison -- unless Aidan and Meg can follow a trail of clues to prove their innocence. The problem? Right now they're trapped in a juvenile detention center. Until they escape one night -- and find themselves on the run, both from the authorities and from a sinister attacker who has his own reason to stop them.

It's every brother's worst fear: As Aiden and his sister, Meg, are walking home from school one day, a van pulls over and Meg is kidnapped. Aiden is the only witness to his sister's disappearance. Why has Meg been kidnapped? As a vendetta against Meg and Aiden's parents? Or is there an even bigger conspiracy at work? While Meg fends off her kidnappers and plans an escape, Aiden must team up with the FBI to find her - tracking down clues only a brother could recognize.

The morning after Hurricane Leo rips through the town of Canaan, residents awaken to widespread destruction—power outages, downed branches, uprooted trees, broken windows and damaged roofs. Four eighth-grade friends—Evan, Jason, Mitchell, and CJ—meet to explore the devastation. The tight-knit group is dismayed to find that Evan has brought along a stray—Ricky, who is new to their town and school, and doesn’t have any friends yet.

Mason and Ty were once the very best of friends, like two nerdy sides of the same coin . . . until seventh grade, when Ava Petrakis came along. Now Mason can trace everything bad in his life to that terrible fight they had over the new girl. The one thing he’d give anything for is a do-over. But that can’t happen in real life—can it?

Reef and Theo don't know what's happening to them. They'll be going about their days and then suddenly they'll have these strange flashes of memory—but the memories don't belong to them. And at the same time, their own memories are starting to... vanish. For Reef, this is a big problem, because memories are all he has left of his mom. For Theo, it's strange because the new memories give him a freedom he doesn't have with his domineering dad.

As the son of Hades, Nico di Angelo has been through so much, from the premature deaths of his mother and sister, to being outed against his will, to losing his friend Jason during the trials of Apollo. But there is a ray of sunshine in his life—literally: his boyfriend, Will Solace, the son of Apollo. Together the two demigods can overcome any obstacle or foe. At least, that's been the case so far . . . Now Nico is being plagued by a voice calling out to him from Tartarus, the lowest part of the Underworld.

Magnus Chase has always been a troubled kid. Since his mother's mysterious death, he's lived alone on the streets of Boston, surviving by his wits, keeping one step ahead of the police and the truant officers. One day, he's tracked down by an uncle he barely knows - a man his mother claimed was dangerous. Uncle Randolph tells him an impossible secret: Magnus is the son of a Norse god. The Viking myths are true. The gods of Asgard are preparing for war. Trolls, giants and worse monsters are stirring for doomsday.

Since their mother's death, Carter and Sadie have become near strangers. While Sadie has lived with her grandparents in London, her brother has traveled the world with their father, the brilliant Egyptologist, Dr. Julius Kane. One night, Dr. Kane brings the siblings together for a "research experiment" at the British Museum, where he hopes to set things right for his family. Instead, he unleashes the Egyptian god Set, who banishes him to oblivion and forces the children to flee for their lives.

When best friends Dak Smyth and Sera Froste stumble upon the secret of time travel - a hand-held device known as the Infinity Ring - they're swept up in a centuries-long secret war for the fate of mankind. Recruited by the Hystorians, a secret society that dates back to Aristotle, the kids learn that history has gone disastrously off course. Now it's up to Dak, Sera, and teenage Hystorian-in-training Riq to travel back in time to fix the Great Breaks . . . and to save Dak's missing parents while they're at it.

Ana Dakkar is a freshman at Harding-Pencroft Academy, a five-year high school that graduates the best marine scientists, naval warriors, navigators, and underwater explorers in the world. Ana's parents died while on a scientific expedition two years ago, and the only family's she's got left is her older brother, Dev, also a student at HP. Ana's freshman year culminates with the class' weekend trial at sea, the details of which have been kept secret. She only hopes she has what it'll take to succeed.