Bone Island: A Hollow Tree Mystery in Bloomington, MN

Molly and Michael Russell, twins who, at a very young age, lost their parents in a car accident that wasn't an accident, are being raised by Gunther and Willa, the body guard and secretary to their father. They've always thought their frequent moves from one place to another and the insistence of their caretakers that they wear some form of disguise when they are out in public was only a fun game Now that they are thirteen, it's not a game anymore and when Molly is twice attacked by a stranger, they demand to know why and who is threatening them.