One night in the biting autumn wind, Cheung Sing-hei (played by Tracy Cheng), a Correctional Services Department supervisor, gave vent to his inner hatred and grabbed a wrench to beat his stepfather Tsang Shu-leung (played by Law Lok-lam). After the incident, the police found a wrench stained with the blood of the deceased and Sing-hei's fingerprints near the crime scene based on the testimony of notary boss Tang Lap-yin (played by Kouri Kuok). With solid evidence, Sing-hei was found guilty of manslaughter and sentenced to 13 years in prison.