MAN and KIU are shocked to find that the newly appointed sergeant is a member of KEUNG’s gang named CHEUNG KING-FUNG. FUNG is in fact an undercover police officer who managed to infiltrate the drug trafficking ring. Believing that FUNG has something to do with LAM’s death, MAN and KIU have both shown open hostility towards him. KIU discovers that FUNG is not only unfamiliar with the standard operating procedures but also tends to be a bit too violent while in the execution of his duty. MAN therefore submits an anonymous letter of complaint against FUNG. Upon receiving the complaint letter, NI asks FUNG for an explanation. The two of them have a serious argument over the matter, which greatly shocks and embarrasses CHEUNG NIM-YAN, who is FUNG’s sister and NI’s subordinate in the Miscellaneous Enquires Sub-unit. NI and FUNG have been divorced but YAN and NI’s father YUEN MOON are desperate for them to get back together……