A talented policeman, Lieut. Mud has recently joined a special investigation team at the police headquarter. His duty is to investigate the smuggling of a luxury car. He took over a car that once belonged to former detective Lieut. Siam who was branded as a bad policeman and shot to death by a drug dealer. To make matters more complicated, a female journalist working on the car-smuggling case appears on the scene. Moreover, Prosecutor Liu, the ex-girlfriend of Lieut. Siam wants to turn over the closed case of her ex-boyfriend. However, this case has something filthy: all the witnesses of Lieut. Siam who stood in court are gone except for one drug-addicted girl.