Greystone secrets

"What makes you 'you'? Chess has always been the protector of his younger siblings, Emma loves math, and Finn acts silly so he will be adored. They've been a happy family, the three of them and their mom. But everything changes when reports of three kidnapped children--who share the same first and middle names and exact birth dates--reach the Greystone family. This bizarre coincidence makes them wonder: Who exactly are these strangers? Before Chess,...

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.