高級警司江高逸泰（吳岱融）在警隊升職典禮中被人脅持，O記高級督察高家俊（吳卓羲）眼見父親身陷險境束手無策，千鈞一髮之際，任職飛虎隊的大兒子高家郎（黃宗澤）以精準槍法相救，然而這一發子彈牽起了高家埋藏已久的心結。警隊的臥底接連被殺，新型毒品泛濫，恐怖組織來勢洶洶……在錯縦複雜的事件中，警司聶宇航（苗僑偉）竭力搗破背後惡勢力，家郎、家俊兄弟各自面對自己感情困境的同時，亦被迫走上不同道路對立交鋒……

During a promotion ceremony for police officers, Senior Superintendent KO YAT-TAI (Hugo Ng) is taken hostage. Seeing his father in danger, OCTB Senior Inspector KO KA-CHUN (Ron Ng) is unable to do anything. In a split second, YAT-TAI’s elder son KO KA-LONG (Bosco Wong), a member of the Flying Tigers, demonstrates his excellent marksmanship to save him, which unexpectedly acts as trigger to bring what was buried in the KO family back to light. A recent spate of murders of undercover cops, a surge of new drugs, and terrorist groups are portent of a menacing future…… Confronting complications, Superintendent LIP YU-HONG (Michael Miu) fights relentlessly to bust a criminal mastermind. Meanwhile, caught in their own relationship dilemma, two brothers, KA-LONG and KA-CHUN, end up going their separate ways , turning into rivals……