Margaret Peterson Haddix

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...

One minute the teens are there playing and laughing, the next they have disappeared from the lawn at the house next door, and Marin cannot believe it. When she meets Charley she discovers she is not the only one who has seen the teens, and Charley calls them the "Remarkables." Charley warns Marin not to approach them, but Marin can't stop thinking about something that happened back in her old house, and wondering if the Remarkables could help her--or...

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.

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.

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.

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.

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.

Kiandra Watanaboneset reluctantly takes charge when she, her brothers Enu and Edwy, and some young friends are captured by Enforcers and sent to a prison on the planet Zacadi.

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 Romanovs and the mystery surrounding their deaths.

Twelve-year-old twins Nick and Eryn and their robot stepsiblings, Jackson and Ava, try to save humanity from killer robots.