景城市公安局以何不可为首的刑警一直在调查岳城团伙贩卖毒品一案，因证据不足，一直无从着手，一天，刚好何不可遇到岳城涉嫌杀人，并将其带回警局。 凶手杀害罗晓蓝是想拿回刻有岳城集团所有犯罪证据及资金情况的密码的一个价值连城的钻石项链，罗晓蓝死后，只有洛小梅知道项链藏在哪儿。警方希望以故意杀人罪起诉岳城，并顺腾摸瓜寻找 他的贩毒和其他案件的证据，将其贩毒组织一网打尽。为了自己的贪念起初的洛小梅并不配合警方， 使案件调查陷入僵局。。。。

The criminal police headed by He Bu from the Jingcheng City Public Security Bureau have been investigating the drug trafficking case of the Yue Cheng gang. Due to insufficient evidence, they have been unable to start. One day, He Bu happened to encounter Yue Cheng suspected of murder and brought him back to the police station. The murderer killed Luo Xiaolan because he wanted to get back a priceless diamond necklace that was engraved with the password of all the criminal evidence and financial status of the Yuecheng Group. After Luo Xiaolan died, only Luo Xiaomei knew where the necklace was hidden. The police hope to prosecute Yue Cheng for intentional homicide, and search for evidence of his drug trafficking and other cases, so as to wipe out his drug trafficking organization. For her own greed, Luo Xiaomei did not cooperate with the police at first, which brought the case investigation to a deadlock.