In the south of Laos, an American volunteer doctor becomes a fugitive after he intervenes in the sexual assault of a young woman. When the assailant's body is pulled from the Mekong River, things quickly spiral out of control.

　　在隐蔽的缦城角落，利欲熏心的贩毒集团不择手段，致使无数人因沾染毒品而家庭破碎、坠落深渊。被毒贩迫害至家破人亡的张耀（张家辉 饰）为复仇，与缉毒队长安渡（阮经天 饰）暗中合作，二人联手做局狠辣除害，