Tang Zhaoning found a mark on the body at a crime scene. What she didn't know was that her father had seen that mark fifteen years ago and recorded it in his police log, but now it was buried deep in the locked drawer of her immediate boss Gao Min's desk. It was the mark of a flat boat. Back at the bureau, a young psychology expert came to help them solve the case, but this young criminal psychology expert Pei Siheng was like a fog. He always felt that there was something hidden, and from his behavior, it seemed that he also recognized the mark on the deceased? As the case was investigated step by step, Tang Zhaoning discovered that this seemed to be more than just an ordinary murder case. More and more people were involved behind it, including her boss, her father, her father's friend Uncle Chen, and... Pei Siheng. He also has secrets and an unspeakable past. No matter what the truth is in the end, Tang Zhaoning vows that she must find out the truth for the sake of clarity in the world and justice for the dead!
