In the late summer of 2004, a small city named Longchun (陇春) in northern China is beset by a series of brutal murders. Most people, while anxious, believe this has nothing to do with them.
And so does Xu Yuan (许缘), a forensic science student enjoying her summer break. But after she starts working part-time at a rare trendy café in the city, strange happenings begin to shadow her steps, like snakes rustling through the grass.