Former Hong Kong Correctional Services personnel Cheung Sing-hei (Kevin Cheng) was sent to prison for murdering his stepfather. The key witness of the case turns out to be his cousin and best friend Tong Lap-yin (Roger Kwok). Ten years later, Hei is released from prison. Yin is now one of the most influential people in the city while Hei's reputation and future are in ruins. Feeling extremely frustrated and harbouring suspicions about the case ten years ago, he is desperate to find out the truth behind his stepfather's death. After some investigation, Hei realises who the real killer was, but there appears to be no motive. More importantly, evidence is also lacking. This story is about how Hei exposes the truth and ultimately proves his innocence.