A mysterious man used police no. 80343 to forward the application form to MUI to take away evidence. Mill gave him a camera bag. NGAU received the bag from that mysterious man which was full of heroin. He rewarded him with three hundred thousand dollars. The police superintendent failed to interrogate police no. 80343 and suspected that there might be undercover. Therefore, he ordered SIR WONG and SIR CHEUNG from ICAC to investigate. SIR CHEUNG recognized that police 80343 had discovered NGAU of drug traffic and planned to take the evidence before going to court. However, someone had done before him. NGAU received a call and gave two hundred thousands dollars to a man who in fact was Sergeant SUN. NGAU was brought back by ICAC and being suspected of bribing policeman for taking evidence .