Zhang Ying (Aoi sora) is a mentally handicapped female student, and Chen Jie (Juno Mak) is an ordinary schoolbag seller. They are secretly in love. One day, Du Ge (Liu Yong), a drunken police captain, saw Zhang Ying and mistakenly thought she was a prostitute and wanted to have sex with her. Chen Jie wounded Du Ge and took Zhang Ying. They went to the police station to report the case, but they didn't want to go into the lion's den. Zhang Ying was gang-raped by Du Ge in the police station, and Chen Jie was beaten and framed in prison.

Chen Jie was determined to get revenge after he got out of prison. There have been two consecutive murders in this city in which pregnant women were forced to give birth by caesarean section. One of the husbands of two pregnant women was killed and the other was missing. Police investigations revealed that the two male victims belonged to the same plainclothes detective team. The remaining players Fu Xie (Xiao Hao) and Guohua (He Hua Chao) immediately contacted the retired captain Du Ge and warned him to be careful, because Fu Xie had a hunch that cold-blooded killer was coming for their plainclothes team.