The Castle on the Hill at the Edge of the World — Scott William Carter

If everybody would just leave Sam alone, she'd be perfectly happy hanging out in The Land Between, the undeveloped forest at the end of the street where she can pretend, at least for a little while, that life is much better than it really is. Then a strange boy moves in next door and all her problems get a lot worse.Rob (or does he go by Bobby?) insists that his parents are prisoners in a mysterious castle in another world. Others claim the truth of his past is far more tragic. When her new friend vows to rescue his parents or die trying, Sam must make a fateful choice that will change both their lives forever — and reveal just how thin the line between imagination and hope can really be.