Margaret Peterson Haddix

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

"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 letters--and find out what really happened to best friends Rosemary and Toby way back in the 1970s. Meanwhile, across town, Nevaeh also finds a mysterious letter. But this one reads like a confession to a crime. And Nevaeh knows her father, the 'Junk King,' expects...

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,...

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.

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.

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.

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.

Jonah was able to save all of time from collapsing but in doing so gained a twin brother, Jordan, who must learn what has happened and do his own part to save time--and his parents.

Twelve-year-old twins Nick and Eryn investigate why their mother and new stepfather are keeping secrets, why they are forbidden to meet their stepsiblings, and, most important, why their lives are in danger.