Margaret Peterson Haddix

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

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.

Throughout the hunt for the 39 Clues, Amy and Dan Cahill have uncovered history's greatest mysteries and their family's deadliest secrets. But are they ready to face the truth about the Cahills and the key to their unmatched power? After a whirlwind race that's taken them across five continents, Amy and Dan face the most the difficult challenge yet -- a task no Cahill dared to imagine. When faced with a choice that could change the future of the world,...

"In the dazzling conclusion to the Greystone Secrets series from New York Times bestselling author Margaret Peterson Haddix, the Greystones and their doubles, the Gustanos, must team up to save the alternate world--before both worlds are lost. All secrets are revealed in this page-turning, suspenseful story that shows the importance of teamwork, telling your story, and taking action when it matters most."--

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.

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

Twelve-year-old Zola, who has a surprising connection to Jessie, discovers that she is stuck in a fake utopian future, and that those around her are counting on her to help them escape.

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 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 society that allows families to have only two children, third child Matthias joins the Population Police to infiltrate their system.