When his wife and daughter are senselessly murdered, a grieving man finds himself caught up in a war between a group of charismatic vigilantes and the crime that infests their city.

There is an old wives tale that you should hold your breath when passing by a cemetery because an evil spirit rejected by both heaven and hell can get inside of you when you inhale. Somewhere in a carload of college kids on holiday doesn't follow the rules when driving by a graveyard, allowing a spirit of a recently executed serial killer to get inside him/her to begin a killing spree of body-jumping carnage.

罪孽横行的墨西哥某地，连神职人员也自甘堕落。某教堂主教与毒品贩子查沃（戴维·卡斯托 David Castro 饰）相勾结，强迫修女们制作、运输毒品。在一次毒品交易过程中，一包丢失的白粉导致两名修女被杀，侥幸逃生的莎拉修女（Asun Ortega 饰）则被查沃抓进自己的娼馆，更遭到非人的虐待。奄奄一息的莎拉修女得到某个黑市医生的救助，她似乎在昏迷中听到了上帝的教导，指引她拿起武器荡涤世界上的肮脏与罪恶。 一年之后，莎拉修女卷土重来，对堕落的神职人员展开了血腥的大清洗，更将最终目标锁定在恶贯满盈的查沃身上。神罚降临，无人能免……

构思源自同名纪录片，这部医务剧以全美最忙碌，名声也最不堪的洛杉矶县医院的急症室为故事背景。一群医术精湛的医生尽管受制于落后的制度，但他们仍为理想、为病人努力奋斗。