Ran Yan is a forensic examiner and she figures out the cause of death to free her teacher. He plans to kill them anyway and they run away. Her teacher escapes into the water and she gets saved by an assassin. When she wakes up, she learns that her mom is forcing her into a marriage and runs away. Xiao Song is in charge of catching Liu Can and he predicts he will make the deal at a brothel. While there he encounters Ran Yan escaping from her marriage. During a performance there, Liu Can is murdered. The assassin is there and tries to escape by threatening Ran Yan. Ran Yan buys him time to escape by saying that the victim wasn't strangled to death. She finds that his cause of death was a needle in the head. (Source: jindreame at MyDramaList)