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 future where the law limits a family to only two children, third-born Luke has been in hiding for the entire twelve years of his life, until he enters boarding school under an assumed name and is forced to face his fears.

Time travelers Jonah and Katherine arrive in 1611 to rescue missing child John Hudson, son of the explorer Henry Hudson, but just as the mutiny on the Discovery is supposed to start, Jonah and Katherine's knowledge of history is tested once again, and they fear that more is at stake than just one boy's life. Author's note includes facts about Henry Hudson's explorations.

After returning the missing children from history to their original time periods, thirteen-year-old Jonah must save time itself when aviator Charles Lindbergh mysteriously appears and kidnaps Jonah's sister.

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.

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.