Gen Ziegler left her home in tiny Mount Ebal, Pennsylvania right after college, to get as far away from her mirror-image twin, Sara, and their dysfunctional relationship as possible. Now, five years later, Dr. Ziegler teaches at the University of Arizona and assists the Tucson Police as a forensic psychologist. Yet, all her life Gen's had clairvoyant flashes, telling her when Sara was in danger. One new vision is so vivid, Gen flies home to find that...