Set in a fictional city, a story about solving crime through forensic science leads to a serial murder case from 20 years ago. While assisting the police in their investigation and trying to reverse the case involving her father, female forensic doctor Song An Yan joins hands with hot-blooded detective Liu Zhi Ming in their desperate search for the truth. Along the way, they cross paths with the mysterious Lin Xiao Mei.
Mainland-born Liang Huan came to Hong Kong with her daughter Li You Hao in the 1980s to be reunited with her husband, Li Gao Shan. However, he dies unexpectedly, leaving Liang Huan to fend for her late husband's teahouse.
Cheung Sung-bong is a highly respected cop with a long history of success in dangerous cases. However, his past soon comes back to haunt him when a former protégé resurfaces, seeking revenge.
