The story focuses on ex-policeman Gao Feng who was born in a family of public security investigating the truth of his father's case.

An unidentified female body was found in a cave in outskirts of Longwan. A man suddenly showed and required for a DNA match with the body. The latter turned out to be his mum Luo Hongying who was the missing suspect of the case 20 years ago which was handled by Gao Jianshe. Gao Feng who is Gao Jianshe's son found the connections between those leads and decided to find out the truth about his father's death.—Yang Ge