George and Harold, and their doubles, Yesterday George and Yesterday Harold, have a good thing going. Two of them go to school, while the other two hide in the tree house and play video games all day-then they switch! But when their malicious gym teacher, Mr. Meaner, creates a method of mind control that turns their fellow students into attentive, obedient, perfect children, the future of all humanity will be in their hands!

Three sixth-grade boys band together to build an experimental aircraft, enduring social and practical difficulties in the process.

The Invention Hunters visit a child's home in their flying museum, where they learn how electricity works.

"A.J. and the gang from Ella Mentery School start a company to sell their brand new invention-a heated, scented, talking toilet seat!"-- Provided by publisher.

Children attempt to catch Santa Claus as he delivers their presents on Christmas Eve.

"It is up to Nick Slate to find the last of Nikola Tesla's powerful inventions--or face devastating consequences"-- Provided by publisher.

Neglected by her father who spends all of his time building a ghost machine to bring her mother back from the dead, twelve-year-old Emmaline decides that the only way to bring her father back will be to make the machine work, or destroy it forever.

Traveling back to 1890s New York City and the laboratory of Nikola Tesla to ensure history stays on track, the Timekeepers scour the city in search of Tesla's newest invention when the time pirate DeLay steals the machine.

"When a freak spring blizzard buries Starwood Park, Freddie works with Mr. Vaslov to clear the sidewalks using a new invention--Zapato Power snowshoes. But not even the snow can stop a thief from causing trouble in the neighborhood. Can Freddie solve the case, even if it means helping Erika, the Starwood Park bully?"-- Provided by publisher.

When Finley decides that fashion is just wearable art, she sets out to create a new fad with her friend Henry: a forklet, a bracelet you can both wear and eat with and only one dollar each for her classmates--unfortunately her parents do not appreciate the disappearing silverware, and Finley has to rethink her invention.