Fai Yan (Chow Ka Lok) and his sworn sister Ko Keung (Joey Wong) become Lo Yan County constables for the money. Their captain, Wong Se (Raymond Cho), sends Fai Yan to the chaotic Yat Tseung Kung City to find a missing spy. Through a mishap, Boon Lung Sect’s minion Moyung Gong-tsz (Brian Chu) brings Fai Yan there. The city appears prosperous, but its four major sects secretly battle for power. The late sect leader decreed that whoever draws the Infernal Sword will marry Tsui Yi Sect’s Fu Ling (Jeannie Chan). Fai Yan and Gong-tsz accidentally draw it together, making them unexpected rivals. As the sects scheme and the spy’s identity remains elusive, Fai Yan finds himself entangled in a web of intrigue—whether fortune or misfortune remains to be seen.