Prologue

There is a mystery in my house.
A girl, with no intentions of revealing her past, has lived in my house for the past two months. She arrived, without warning, sprawled in our backyard, and spoke one phrase in a language that sounded like German, but wasn't.
Callie has promised to tell us about her past when it catches up to her. But when it does, my family-and planet Earth-are thrown into a war beyond our homes.