Former investigator Fang Yiren (played by Zhang Xiaoquan) started a new life with journalist-turned-PR manager Xu Haiyin (played by Xu Weining) and their daughter Jiang Xiaomeng (played by Moon Lee). However, Fang Yiren was involved in a series of deaths and became the number one suspect. These incidents are related to a murder case he took over 15 years ago. Prosecutor Zhang Genghao (played by Fujioka Dean) suspected that Fang Yiren and his mentor Lin Jingrui were hiding something. Fang Yiren worked with Inspector Zhao Chengkuan (played by Wang Shixian) and forensic doctor Xue Xinning (played by Su Huilun) to uncover the truth and prove his innocence, otherwise he would face the risk of breaking up with Jiang Xiaomeng again.