Detectives Bang Je-su and Oh Yeong-dal are partners fighting crime in the streets of Seoul. Oh Yeong-dal is a veteran and has settled in to the police force after years of service. Bang Je-su is a rookie who is out to find as much action as he can.

Partnered up, they try to make the most of their work, but when a string of brutal serial killings occur, they have to try to put everything behind them to catch some of the most ruthless killers they'll ever meet!