Margaret Peterson Haddix

Told from separate viewpoints, as evil forces from the parallel world invade their home, the Greystones, their doubles, and friends must return to the alternate dimension to save both worlds.

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,...

When Colin and Nevaeh both find mysterious letters dating back to the 1970s, one of which reads like a confession to a crime, their new friendship is threatened when this letter pits their families against each other.

Delving into the power of privilege, the importance of true friendship and the question of humanity and identity, this novel follows fifth grader Max as he searches for his best friend who disappeared, leaving behind a strange note.

In a future where a law limits a family to only two children, third-born Luke has been 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.

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.

In a future world of false identities, government lies, and death threats, Luke feels drawn to the younger brother of the boy whose name Luke has taken.

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.

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

Jonah, thirteen, and Katherine, eleven, travel through time to 1918 Russia just as Alexei, Anastasia, and the rest of Tsar Nicholas II's family is about to be executed. Author's note includes facts about the Romanov's and the mystery surrounding their deaths.