Lik-kei catches sight of Chun-tung while he and his subordinates are raiding some brothel. Lik-kei pursues him and reaches some unit. Ho-fan follows from behind and notices Chun-tung’s female accomplice. Chun-tung is restrained by Lik-kei in a back alley. Some assassin fatally shoots Chun-tung and even points a gun at Ho-fan. Lik-kei instinctively pulls Ho-fan away. But Ho-fan accidentally bruises his head and passes out. Ho-fan comes round and then cannot recall the course of events in the shooting incident. But he remembers he had seen Chun-tung’s female accomplice in the office. Lik-kei tells Ho-fan how to ask the company secretary to let him see CCTV footage, alerting Ming-kwan, Chung-ying and their chums. Lik-kei is then suspended from duty as Ching-ying zeros in on him. Lik-kei goes to see Ho-fan. He suspects someone is going to harm him. Suddenly, a gun-wielding mysterious person snipes at Ho-fan.
Because of a fatal shooting case, plain-clothes Sergeant Ko Lik-kei runs into a “dull” and “troublesome” witness called Lee Ho-fan. Lik-kei is instructed to protect Ho-fan at all times. Initially, the duo are strangers that cannot stand each other. They then gradually get along. Meanwhile, an apparel company of which Ho-fan is a major shareholder is found to have involved in illicit dealings. Yip Cheung-lok and his son Yip Ming-kwan, who are member of senior management, are associated with these activities. Lik-kei teams up with Ho-fan and Ho-fan’s younger sister Lee Chung-ying, who is a barrister by profession, to investigate. Lik-kei and Chung-ying get entangled in a relationship in the process. Also, Lik-kei’s elder sister Ko Wing-yumand Ho-fan get along sometimes and provoke each other at other times. Fate has brought the foursome together, causing a case that has remained unsolved for more than twenty years to be reopened.
