Thirteen-year-old Nina is imprisoned by the Population Police, who give her the option of helping them identify illegal "third-born" children, or facing death.

When thirteen-year-old Luke Garner unwittingly sets off a rebellion which sweeps the country and ousts the Population Police from power, he quickly realizes that the new regime is corrupt and he may hold the only key to true freedom.

In a future where the Population Police enforce the law limiting a family to only two children, Luke has lived all his twelve years in isolation and fear on his family's farm, until another "third" convinces him that the government is wrong.

In a society that allows families to have only two children, a group of third-borns tries to save themselves and others like them.

Kiandra Watanaboneset reluctantly takes charge when she, her brothers Enu and Edwy, and some young friends are captured by Enforcers and sent to a prison on the planet Zacadi.

When thirteen-year-olds Jonah and Chip, who are both adopted, learn they were discovered on a plane that appeared out of nowhere, full of babies with no adults on board, they realize that they have uncovered a mystery involving time travel and two opposing forces, each trying to repair the fabric of time.

Jonah was able to save all of time from collapsing but in doing so gained a twin brother, Jordan, who must learn what has happened and do his own part to save time--and his parents.

Jonah, Katherine, Chip, and Alex suddenly find themselves in 1483 at the Tower of London, where they discover that Chip and Alex are Prince Edward V and Richard of Shrewsbury, imprisoned by their uncle, King Richard III, but trying to repair history without knowing what is supposed to happen proves challenging. Author's note includes historical facts about the princes and king.

When Jonah and Katherine travel to early 1900s Switzerland and Serbia to return Albert Einstein's daughter, Lieserl, to history, her mother Mileva grasps entirely too much about time travel and has no intention of letting her daughter go.

Follows fifth grader Max as he searches for his best friend who disappeared, leaving behind a strange note.