Rachel and Alice are an extremely rare kind of identical twins-so identical that even their aunt and uncle, whom they've lived with since their parents passed away, can't tell them apart. But the sisters are connected in a way that goes well beyond their surfaces: when one experiences pain, the other exhibits the exact same signs of distress. So when one twin mysteriously disappears, the other immediately knows something is wrong-especially when she starts experiencing serious physical traumas, despite the fact that nobody has touched her. As the search commences to find her sister, the twin left behind must rely on their intense bond to uncover the truth. But is there anyone around her she can trust, when everyone could be a suspect? And ultimately, can she even trust "herself"?