During China's Warring States period, a district prefect arrives at the palace of Qin Shi Huang, claiming to have killed the three assassins who had made an attempt on the king's life three years ago.

The film mainly tells that Lin Hongying, a trainee police officer, has finally joined the serious crime team of the Public Security Bureau after a rigorous test. The choice between love and hate is put in front of Lin Hongying.