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。
After attending a medical conference in Beijing and coming frighteningly close to dying in a car crash, Dr Matthew Nolan, played by Armitage (Obsession, Stay Close) arrives home and is immediately arrested at London’s Heathrow Airport. Exhausted and confused, Nolan is accused of the murder of a woman who was in the car he crashed. DC Hana Li, played by Lusi, is the no-nonsense, London officer charged with accompanying Nolan back to Beijing, but plenty happens on the way.
