Margaret Peterson Haddix

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,...

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.

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 are summoned to help another missing child from history, this time Virginia Dare from the Roanoke Colony, but their journey is sabotaged and goes dangerously awry, leaving them in the wrong time period. Includes author's note about the history of Roanoke Colony and Virginia Dare.

Eleven-year-old Marin and her neighbor Charley hope that by preventing a disaster that occurred twenty years ago, they can save Charley's dad from a future of guilt and self-destructive behavior.

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.

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.

A twelve-year-old girl raised in a foster village is returned to her biological parents, and discovers home is not what she expected it to be.

Told from separate viewpoints, as Finn, Emma, and Chess Greystone and Natalie Mayhew, ages eight to thirteen, continue their quest to rescue their mothers they must return to the alternate dimension where truth is illegal.

Thirteen-year-old Bethany's parents have always been overprotective, but when they suddenly drop out of sight with no explanation, leaving her with an aunt she never knew existed, Bethany uncovers shocking secrets that make her question everything she thought she knew about herself and her family.