World famous prosecutor, Marcia Clark, investigates the disappearance of 23-year-old mother of four, Stacy Peterson, who vanished without a trace. As the world searched for her, all eyes began to focus on her cop husband Drew Peterson when it was discovered his previous wife died suspiciously. Is Drew Peterson responsible for both of his wives' deaths? Marcia will dissect the first 48 hours of this case to try to discover exactly what happened to Stacy Peterson.