Shuang Ye (Qin Lan), a rich woman who once lived a stable and happy life, is clouded by the unexpected disappearance of her husband Ling Feng (Gao Shengyuan) and her daughter. After consulting with his father Ye Cheng (Yam Tat-wah), Shuang Ye called the police, but met her boyfriend Yao Jie in college again. Yao Jie, the police officer who led the case, is an expert in criminal psychology who returned from studying in Britain, and also a detective who declared his identity. At the beginning, the two broke up because of different choices and incompatible personalities. In the process of solving crimes, Yao Jie, who is good at solving crimes from details, took aim at Ye. However, his arbitrary and conceited personality made Shuang Ye, who was already anxious, very angry. When Shuang Ye accused Yao Jie of reasoning in the wrong direction, his father's behavior became suspicious and complicated. Ye Cheng, who raised his daughter alone, is a successful business celebrity. He loves her deeply and intends to hand over his business empire to his son-in-law Ling Feng. However, after Ling Feng disappeared, he frequently contacted mysterious people and ordered them to kidnap his daughter Shuang Ye on a rainy night. But the mysterious man was immediately killed by a man who claimed to be Xiao Qiang (Gao Xin), and the police came to rescue Shuang Ye. At this point, Yao Jie has found Ling Feng and successfully rescued Ling Feng's father and daughter. The family was immersed in the joy of reunion and cried, but Ye died unexpectedly at this time. Next to the place where Ye Cheng died, the police dug up the skeleton of a woman who had been dead for twenty years. Shuang Ye and Ling Feng, a family reunion, should be happy, but full of worries, all this can't escape Yao Jie's eyes. Yao Jie explained to Shuang Ye that in the process of solving the case, Shuang Ye was shocked by the amazing secret hidden behind him for 20 years. She decided to stage another kidnapping with Yao Jie to trace the real motive behind the fog.