In Kyoto during the Song Dynasty, Su Jinli, a concubine, aspired to study medicine and investigate crimes, and worked hard to solve the mystery of her mother's death. The young general Lu Yixuan suffered a lot from his stepmother and lost contact with his family. A bizarre murder causes the two to meet again without recognizing each other, and a secret love develops while they work together to investigate the case. However, the prince was poisoned, and the disputes over the heir apparent continued. As they searched for the truth in the fog, could they get what they wanted and return to the south of the Yangtze River?
