半年间，SNK剧变，总监余英飞离职、门外汉古肇华空降。张家妍虽掌权却难服众。刘艳的公开平台崛起，动摇传统媒体地位，连已入官场的许诗晴亦被卷入新旧媒体的角力。文慧心于此时复出，昭告世人：新闻女王的地位永远不可撼动！
As Leo's replacement Thomas Chamberlain arrives Nikki investigates the murders of Rachel Freedman, shot in the head, and her little autistic son Nathan, who was poisoned. Nikki rejects policewoman Anne Burchett's theory that Rachel killed them both but is perturbed when an impostor, claiming to be Rachel's sister, visits the morgue. At the same time the disfigured corpse of Eva Liron is discovered, killed with the same poison as Nathan. She had been the nanny to French hot shot footballer Isaac Dreyfus and was planning to blackmail him over a sex tape of them both. Jewish Isaac is a controversial figure due to his anti-Muslim sentiments but he denies ant part in the murders. Then another victim, Isaac's agent Mousa, is discovered dead.
故事发生在明朝末年，胡、苗、范、田四家人本是至交，却因为一场误会而结下了血海深仇，其后人们更是为了争夺明室遗留下来的宝藏而大打出手死伤无数。胡一刀（吕良伟 饰）侠肝义胆想要使沉冤得雪消除误会，却遭到了田归农（曾江 饰）的陷害最终命丧苗人凤（谢贤 饰）手下。 胡一刀的妻子郎剑秋（戚美珍 饰）死前将儿子胡斐（吕良伟 饰）托付给了平四，长大成人后的胡斐发誓要杀死苗人凤替父母报仇。胡斐继承了祖传的《胡家刀法》，习得了一身好武艺闯荡江湖，邂逅了名为袁紫衣（周秀兰 饰）、程灵素（景黛音 饰）等身世复杂的江湖女子，牵扯出了一段荡气回肠的武林传奇。
在第四季中，新势力正竞相填补俄罗斯人留下的权力真空，Mike对金斯敦的控制受到威胁，迫使他不得不面对由此引发的帮派战争，阻止他们吞并这座城镇。与此同时，他的所爱之人面临前所未有的危险，Mike必须应对一位固执的新典狱长，以保护自己的人，同时与来自过去的恶魔作斗争。
