Undercover detective Chen Feng Xiang finds himself in a tough spot after a large group of officials transitions to civilian life, but eight years later, he is called back to action by an anti-crime unit. The most troublesome triad leader in the current criminal underworld is none other than Chen Feng Xiang's younger brother, Zhang Zhi Qiang, prompting Feng Xiang to re-enter the "underworld." He joins the anti-crime team led by Zhang Shaojun and begins to confront old friends and enemies, putting Feng Xiang in a difficult position. Three years after returning to Hong Kong, gangs are looking to exploit a major opportunity. While investigating a case involving the disappearance of a leader, Feng Xiang uncovers a massive conspiracy that shakes the century-old history of Hong Kong's triads.
