黑幫「福和」的丁卓飛（謝天華飾）與反黑隊督察段一凡（周柏豪飾）是雙方安插對方陣營的臥底。

丁卓飛在「福和」做了十年臥底，為了掩飾真實身份和迅速上位，他比別人更加心狠手辣，亦因此漸漸接近核心。但親手拷問同袍，看著他們慘死，令丁卓飛開始厭倦這沒有盡頭的臥底工作……

另一邊廂，段一凡在反黑組步步高升，有望成為最年輕的總督察。相戀多年的女友倩揚（連詩雅飾）亦答應了他的求婚。事業愛情皆美滿的段一凡，開始渴望做一個真真正正的警察。他處心積慮想擺脫宋先生（陳啟泰飾）和他背後的「東利貿易」…
一次「福和」及「東利」的毒品交易，原來是「福和」話事人喜哥找出叛徒的調虎離山計—喜哥與宋先生其實在另一地方暗中交易。事件中倩揚更慘遭殺害，殺警的罪名被嫁禍到丁卓飛。

丁卓飛不屈不撓終擒獲殺手後把殺手帶到段一凡面前，二人盤問下殺手承認是受「福和」頭馬肥東指使，但段一凡在找到肥東在「東利」工作的證據後，便肯定幕後主使就是宋先生。段一凡不理會丁卓飛阻止，獨自去找宋先生報仇。原來宋先生早覺得段一凡出現異心，所以要痛下殺手！段一凡隨即被偷襲，丁卓飛及時趕到，打傷宋先生和他的手下。宋先生負隅頑抗，最後段一凡與他同時開槍，二人同歸於盡…

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Fuk Wor Triad member Ting (by Michael Tse Tin Wah) and Senior Inspector Tuen (by Pakho Chau) of the Regional Anti Triad Unit are moles that have been planted by the rival party.

 

 

Within 10 years, Ting has risen through the ranks within the organization, but deep down he is fed-up with the dead-end job as an undercover cop. Whereas for Tuen – the soon-to-be youngest-ever chief inspector, wishes to start off his new chapter in life with a clean slate and free from his inglorious past. He schemes to take down his secret boss, Sung (by Ken Chan) of the illegitimate Eastern Trade Company…

 

 

When Fuk Wor and Eastern Trade join forces on a narcotics deal, little do the two know that it is in fact a trap set up by the masterminds, to uncover the moles’ identity. Peace and justice are long-overdue for the two, but the step towards it could prove fatal…