CHIT tells them that MEI was killed by TING as she has an affair with ON (TING’s husband). YEE and YUNG does not believe CHIT’s words. They further investigate. They apply for reading MEI and HON’s coroner’s report. They find out that MEI and HON had taken too much sleeping pills. Besides, MEI was strangled by a tie and HON hanged himself on the tree. The spot was a villa belonged to Hon's good friend. HON always went there with a mature lady. Moreover, a child states that MEI was a new face to him and she rarely went there. This indicates that MEI is not HON's real girlfriend. Moreover, LAI had also been to Japan five years ago. It is claimed that FUNG tried to catch a special butterfly and unfortunately fell down from the cliff. TING is the only witness. However, LAI finds out that the kind of special butterfly had already extinct as the kind of special bean which those butterflies depended on was in shortage.