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,...

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.

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.

The Greystone kids thought they knew. Chess has always been the protector over his younger siblings, Emma loves math, and Finn does what Finn does best--acting silly and being adored. They've been a happy family, just the three of them and their mom.But everything changes when reports of three kidnapped children reach the Greystone kids, and they're shocked by the startling similarities between themselves and these complete strangers. The other kids...