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.

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".

Ben Ripley may only be in middle school, but he's already pegged his dream job: CIA or bust. Unfortunately for him, his personality doesn't exactly scream "secret agent". In fact Ben is so awkward, he can barely get to school and back without a mishap. Because of his innate nerdiness, Ben is not surprised when he is recruited for a magnet school with a focus on science - but he's entirely shocked to discover that the school is actually a front for a junior CIA academy.

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 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.

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.

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.

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?

Twelve-year-old Theodore “Teddy” Roosevelt Fitzroy believes that Henry, the hippopotamus at the brand-new FunJungle, has been murdered. The zoo’s top brass claim the hippo went belly up the natural way, but Teddy and his feisty friend Summer McCraken have other ideas. Could the culprit be FunJungle’s animal-hating head of operations? Or is it FunJungle’s owner - Summer’s dad - a man who is much more concerned about money than animal welfare? The deeper Teddy and Summer dig, the more danger they’re in - because when it comes to hippo homicide, the truth can’t be caged!

Like his fellow lunarnauts - otherwise known as Moonies - living on Moon Base Alpha, twelve-year-old Dashiell Gibson is famous the world over for being one of the first humans to live on the moon. And he's bored out of his mind. Kids aren't allowed on the lunar surface, meaning they're trapped inside the tiny moon base with next to nothing to occupy their time - and the only other kid Dash's age spends all his time hooked into virtual reality games.