I couldn't find a no-CP tag, so I've tentatively labeled this as having no female lead.
A call for help shatters the quiet at the Xicheng Police Station. Chu Jie, head of the Xicheng Criminal Investigation Team, receives a report that someone has been threatened with death and that a family member has already gone missing. To protect the informant, Chu Jie immediately takes his teammate Su Yang to the address of the caller, Ding Xiaoshan. There, they discover that Ding Xiaoshan is connected to a recent dismemberment case.
As the police investigate openly and in secret, the case gradually comes to light, and an old case from six months ago becomes entangled in the investigation. At last, the avenger hiding in the darkness emerges. The police move in to make an arrest, but the highly vigilant criminal escapes, and criminal investigation team leader Chu Jie is injured in an accident.
Just then, the missing Ding Xiaorou is found dead in a rented apartment. To everyone's surprise, the dismemberment case killer, who had been on the run, also turns himself in. Meanwhile, Ding Xiaoshan, under police protection, senses something is wrong and tries to flee, only to be caught red-handed. At last, the truth comes out: it all began with this so-called informant...
