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,...

Told from separate viewpoints, Chess, Emma, and Finn Greystone, ages twelve, ten, and eight, investigate why their mother went missing and uncover their ties to an alternate world.

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.

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

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.

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.

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.

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 that time in history-and the way echoes from that era affect Colin and Nevaeh themselves. When Colin finds a shoebox full of letters hidden in a stranger's attic, he knows he's supposed to throw them away. That's his summer job, getting rid of junk. But Colin wants to rescue the...

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.

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.