Synopsis：Xia Dan of the Provincial Public Security Department investigates her cousin's death from drug overdose and uncovers a cross-border drug trafficking syndicate. She collaborates with Hong Kong police officer Ka Lung to go undercover, making contact with the gang leader Leng Yue and his superior Li Shaoyuan. Through technical surveillance, the police identify international drug trafficker Toni. To gain her trust, Xia Dan is forced to fatally shoot Ka Lung in front of the drug dealers...