The day before September 1st, 2016, a woman and her four children boarded a crowded train expecting to arrive in Denver, Colorado for a fresh start. But somehow, overnight, the woman mysteriously dies and not a single person on that train can say how. For seven years, the tragic case of Marina Placensia remained unsolved. Until a relentless detective and a groundbreaking medical re-examination blew the case wide open. Listen now to the inspiring pursuit of justice that was finally able to bring a killer to light.