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.

Siblings Alex and Zoe Sherlock take their last name as inspiration when choosing a summer job. After all, starting a detective agency has to be better than babysitting (boring), lawn mowing (sweaty), or cleaning out the attic (boring and sweaty). Their friends Lina, an avid bookworm, and Yadi, an aspiring cinematographer, join the enterprise, and Alex and Zoe’s retired reporter grandfather offers up his sweet aquamarine Cadillac convertible and storage unit full of cold cases. The group’s first target is the long-lost treasure supposedly hidden near their hometown Miami.

Most kids have enough to deal with between school, homework, extracurricular activities, and friends, but Molly Bigelow isn't your typical tween. By day, Molly attends MIST - the Metropolitan Institute of Science and Technology - but it's what she's learning outside of school that sets her apart from her classmates. Molly is a zombie hunter, just like her mother.

When a category three hurricane hits Miami Beach, it uncovers a body buried at the renowned Moroccan Hotel. The body is identified as the man who served as the hotel’s bell captain sixty years ago…and the presumed culprit of the million-dollar jewel heist that took place just before his disappearance.

Florian is 12 years old and has just moved to Washington. He's learning his way around using TOAST, which stands for the Theory of All Small Things. It's a technique he invented to solve life's little mysteries. But when he teaches it to his new friend Margaret, they uncover a mystery that isn't little. In fact, it's huge, and it involves the National Gallery, the FBI, and a notorious crime syndicate known as EEL. Can Florian decipher the clues and finish his homework in time to help the FBI solve the case?

Charlie Thorne is a genius. Charlie Thorne is a thief. Charlie Thorne isn’t old enough to drive. And now, it’s up to her to save the world.... Decades ago, Albert Einstein devised an equation that could benefit all life on earth - or destroy it. Fearing what would happen if the equation fell into the wrong hands, he hid it. But now, a diabolical group known as the Furies are closing in on its location. In desperation, a team of CIA agents drags Charlie into the hunt, needing her brilliance to find it first - even though this means placing her life in grave danger.

After a botched escape plan from her boarding school, Abigail is stunned to discover the school is actually a cover for an elite spy ring called The Center, along with being training grounds for future spies. Even more shocking? Abigail's mother is a top agent for The Center and she has gone MIA, with valuable information that many people would like to have - at any cost. Along with a former nemesis and charming boy from her grade, Abigail goes through a crash course in Spy Training 101, often with hilarious - and sometimes painful - results.

Eli Frieden lives in the most perfect town in the world: Serenity, New Mexico. In this idyllic place, every lawn is perfectly manicured, and everyone has a pool and a tree house. Honesty and integrity are valued above all else. The 30 kids who live there never lie--they know it's a short leap from that to the awful problems of other, less fortunate places. Then one day Eli bikes to the edge of the city limits, and something so crazy and unexpected happens, it changes everything.

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".

Charlie Thorne is a genius. Charlie Thorne is a renegade. Charlie Thorne isn’t going down without a fight. After tracking down incredible discoveries by Einstein and Darwin, Charlie is back. This time, the great ruler Cleopatra has left behind an extremely valuable and powerful treasure, its location encoded on an ancient stone tablet.

When a herd of elephants interrupts the big Friday night football game, the police enlist Teddy and his father to assist them in getting the animals safely back home to the elephant sanctuary. Only when they arrive, their owners realize one of the elephants has gone missing! The lone African elephant, Tanzy, is still out there somewhere.

Dexter Foreman is twelve going on eighty. He has lived at The Pines retirement village with his grandmother since he was six years old, and as a result he gets along better with senior citizens than kids his own age. He's homeschooled by the residents up until the day the county’s truancy officer shows up and announces that Dex has to go to a “real” school, to the local middle school. At school, Dex sticks out like a sore thumb. He dresses like a grandpa (and can be just as cranky). His taste in movies and music is decades out of date.

On a family trip to Paris, Greg Rich's parents disappear. They're not just missing from the city - they're missing from the century. So, Greg does what any other 14-year-old would do: He travels through time to rescue them. Greg soon finds out that his family history is tied to the legendary Three Musketeers. But when he meets them, they're his age, and they'll only live long enough to become true heroes if he can save them.

Cruz Coronado leaves his tranquil home in Hawaii to join 23 talented kids from around the globe to train at the Explorer Academy with the world's leading scientists to become the next generation of great explorers. But for Cruz, there's more at stake. No sooner has he arrived at the Academy than he discovers that his family has a mysterious past with the organization that could jeopardize his future. In the midst of codebreaking and cool classes, new friends, and augmented reality expeditions, Cruz must tackle the biggest question of all: Who is out to get him, and why?

"Are you a gifted child looking for special opportunities?" Dozens of children respond to this peculiar ad in the newspaper and are then put through a series of mind-bending tests, which readers take along with them. Only four children—two boys and two girls—succeed. Their challenge: to go on a secret mission that only the most intelligent and inventive children could complete. To accomplish it they will have to go undercover at the Learning Institute for the Very Enlightened, where the only rule is that there are no rules.