Is Arden crazed by grief, or is she the only one who understands the truth behind her brother's disappearance?

After their parents died in a plane crash years ago, Arden Munro was raised by her older brother Scott. When he disappears after a snowmobile accident shortly after her seventeenth birthday, almost everyone in their small Wisconsin town believes he died in an icy river and that it's just a matter of time before his body is recovered. Arden refuses to accept Scott's death and she begins a desperate—and solitary—search to find him.