Meet the Sinister-Winterbottoms: brave Theo, her timid twin, Alexander, and their older sister, Wil. They’re stuck for the summer with their Aunt Saffronia, who doesn’t know how often children need to eat and can’t use a smartphone, and whose feet never quite seem to touch the floor when she glides—er—walks. When Aunt Saffronia suggests a week pass to the Fathoms of Fun Waterpark, they hastily agree. But the park is even stranger than Aunt Saffronia. Something mysterious is happening at Fathoms of Fun, and it’s up to the twins to get to the bottom of it.

Merci Suarez knew that sixth grade would be different, but she had no idea just how different. For starters, Merci has never been like the other kids at her private school in Florida, because she and her older brother, Roli, are scholarship students. They don’t have a big house or a fancy boat, and they have to do extra community service to make up for their free tuition.

It's been almost a year since Sila's mother traveled halfway around the world to Turkey, hoping to secure the immigration paperwork that would allow her to return to her family in the United States. The long separation is almost impossible for Sila to withstand. But things change when Sila accompanies her father (who is a mechanic) outside their Oregon town to fix a truck. There, behind an enormous stone wall, she meets a grandfatherly man who only months before won the state lottery.

Kate and her younger brother, Tom, lead dull, uninteresting lives. And if their dull, uninteresting parents are anything to go by, they don't have much to look forward to. Why can't Kate have thrilling adventures and save the world the way people do in books? Even her 11th birthday is shaping up to be mundane - that is, until her mysterious and highly irresponsible Uncle Herbert, whom she's never even met before, surprises her with the most unexpected, exhilarating, inappropriate birthday present of all time: a colossal steam locomotive called the Silver Arrow.

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.