Sophia Montgomery, a teenage girl born with the ability to telepathically devour the memories of the dying, witnesses a murder one night at Union Station in Pittsburgh, Pennsylvania. Due to the odd circumstances that brought her to the scene in the first place, her sister, Sybill, convinces her not to report the crime. But despite their efforts to lay low, the sisters become entangled in a labyrinth of murder and deceit, hunted by police and an institution dedicated to quarantining "defective" mutants like Sophia---all while trying to flee a past that should have stayed forgotten.