Margaret Peterson Haddix is one of the most creative authors whose books I've ever read.
In Double Identity the main character, Bethany, has no idea why her family keeps moving and why they leave her to live with an aunt she had never met before. The reader doesn't know why either.
But someone has been searching for Bethany and she is in some sort of danger.
We care about what happens to her and the secret from her past is as great a surprise to the reader as it is to the girl in the story. And finding it out isn't the end of the adventure even though we now know why she's being stalked.
Double Identity was published in 2005, but the events still hold true today. I love the book, and today's kids who enjoy reading will love it, too.