YEE and YUNG check the old file. They find out that the victim named MEI. She committed suicide a year ago together with her boyfriend, HON, who is a foreigner. YEE and YUNG inspect the satchel. They discover a letter which was written by MEI to FUNG (who had died 5 years ago). It depicts how they were persecuted by Butterfly. YEE and YUNG even receive a call front MEI’s spirit. She implores them to clear the case for her. They find out that both FUNG and HON did have an affair with a rich lady, TING, who has married.FUNG is the member of the Butterfly Club. He had been fallen in love with TING. FUNG had fell down from a cliff and died five years ago when he tried to catch a butterfly. HON is TING’s subordinate. CHIT is asked to investigate TING. YEE and YUNG go to MEI's school for some hints. They find out that MEI and CHIT are classmates. CHIT's plot is unveiled.
Louis Koo
徐飞 Tsui Fei
Jessica Hester Hsuan
武俏君 Mo Chiu Kwan (Queen)
Sunny Chan Kam-Hung
江子山 Kong Tze San
Charmaine Sheh Sze-Man
文婉兰 Man Yuen Lan (Man)
Lee San-San
唐心如 Tong Sum Yu
Maggie Siu Mei-Kei
江子青/江子瑶 Kong Tze Ching / Kong Tze Yiu
Andy Tai Chi-Wai
邱彼得 Yau Bei Dak
Samuel Kwok Fung
梁剑雄 Leung Kim Hung
Edmond So Chi-Wai
韩国仁 Hon Kwok Yan (Korean)
Eileen Yeow
邵之蓝 Siu Chi Nam (Gigi)
Timothy Cheng Chi-Sing
刘建生 Lau Kin Sang
Anne Heung Hoi-Lam
梁芊芊 Leung Chin Chin
Catherine Chau
黃琪琪 Wong Kei Kei
Edward Mok
馮添海 Fung Tim Hoi
Henry Lo
曾彥行 Tsang Yin Hang
Cecilia So Yan-Chee
苏惠诗 So Wai Sze
Safina Lam