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,...

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

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

When a diphtheria epidemic hits her 1840 village, thirteen-year-old Jessie discovers it is actually a 1995 tourist site under unseen observation by heartless scientists, and it's up to Jessie to escape the village and save the lives of the dying children.

When thirteen-year-olds Jonah and Chip, who are both adopted, learn they werediscovered 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.

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.

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.

In this page-turning middle grade series by New York Times bestseller Margaret Peterson Haddix, Colin and Nevaeh, whose parents own rival junk-removal businesses, uncover mysteries hidden in attics and basements and discover how trash can become treasure. In The Secret Letters, Colin and Nevaeh find vintage letters that lead to interlocking mysteries from the 1970s and '80s, and they learn about "women's lib," the ERA, and other social issues from...

In 1927, at the urging of twenty-one-year-old Harriet, Mrs. Livingston reluctantly recalls her experiences at the Triangle Shirtwaist factory, including miserable working conditions that led to a strike, then the fire that took the lives of her two best friends, when Harriet, the boss's daughter, was only five years old. Includes historical notes.

Allowing herself to be hypnotized, fifteen-year-old Kira reveals memories of another time and place that may eventually cost her and her mother their lives.