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.

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.

Amy and Dan find themselves in a new global race but this time, everything’s different. Those closest to them might be working for the enemy, and Amy and Dan are forced to ask themselves how far they’re willing to go to save the kidnapped Cahills. How much can you risk when there’s no one to trust?

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.

After angering his father, Zeus, the god Apollo is cast down from Olympus. Weak and disoriented, he lands in New York City as a regular teenage boy. Now, without his godly powers, the 4,000-year-old deity must learn to survive in the modern world until he can somehow find a way to regain Zeus' favor. But Apollo has many enemies - gods, monsters, and mortals who would love to see the former Olympian permanently destroyed.

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.

Sara Martinez is a hacker. She recently broke into the New York City foster care system to expose her foster parents as cheats and lawbreakers. However, instead of being hailed as a hero, Sara finds herself facing years in a juvenile detention facility and banned from using computers for the same stretch of time. Enter Mother, a British spy who not only gets Sara released from jail but also offers her a chance to make a home for herself within a secret MI5 agency. Operating out of a base in Scotland, the City Spies are five kids from various parts of the world.

Fiercetooth, a NightWing obsessed with what could have - and should have - been. Deathbringer, desperate to prove himself as the next great NightWing assassin. Six-Claws, a loyal SandWing, who will soon find that loyalty comes with a price. Foeslayer the NightWing, a dragon in love turned kidnapper, and Prince Arctic of the IceWings, a runaway turned captive. In these four short stories, dig deeper into the world of Pyrrhia to discover what really happened.

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.

After an escaped kangaroo starts a fire that burns down his house, Teddy Fitzroy accepts an invitation to go to Malibu with his girlfriend, Summer, and her mother, Kandace. He’s hoping to spend some time relaxing on the beach, but wherever Teddy goes, trouble isn’t far behind. First, a massive dead whale has washed up on the beach—and before anyone can determine what killed it, it explodes. Doc, the head vet from FunJungle, suspects something fishy is going on and ropes Teddy and Summer into helping him investigate.

In a discontented kingdom, civil war is brewing. To unify the divided people, Conner, a nobleman of the court, devises a cunning plan to find an impersonator of the king's long-lost son and install him as a puppet prince. Four orphans are recruited to compete for the role, including a defiant boy named Sage. Sage knows that Conner's motives are more than questionable, yet his life balances on a sword's point - he must be chosen to play the prince or he will certainly be killed. But Sage's rivals have their own agendas as well.

On his 13th birthday, foster child Alcatraz Smedry gets a bag of sand in the mail - his only inheritance from his father and mother. He soon learns that this is no ordinary bag of sand. It is quickly stolen by the cult of evil Librarians who are taking over the world by spreading misinformation and suppressing truth. Alcatraz must stop them, using the only weapon he has: an incredible talent for breaking things.

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.

Middle school is hard. Solving cases for the FBI is even harder. Doing both at the same time - well, that's just crazy. But that doesn't stop Florian Bates! Get to know the only kid on the FBI director's speed dial - and several international criminals' most wanted lists - in this adventurous series that School Library Journal says combines "elements of Alex Rider, James Bond, and Sherlock Holmes".