Lux Littleton is a brilliant young woman studying in the field of quantum mechanics, and even though she seeks to understand everything about the unobservable universe, nothing can prepare her for the absence she is about to face: the sudden death of her little sister. It's not long before a cloaked, sunken-eyed figure appears at the edges of her consciousness-the same figure that her sister described seeing just before she died. Thus, while grappling...