In the late summer of 2004, a small city named Longchun 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, 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.