A serious traffic accident occurs in the busy city of Hong Kong. The Superintendent (Francis Ng) and Chief Inspector (Nick Cheung) of the CIB Anti-Terrorism Unit arrest a female hacker (Peiyao Jiang). Louis Koo, Superintendent of the Security Wing, believe Francis and Nick are suspicious and requests the Commissioner of Police stop them from handling the case. The investigation expands to Spain and Myanmar. Louis and Nick repeatedly get into conflicts with each other as they work together. From Francis' perspective, he cannot tell whether the two are good or evil, but the Commissioner thinks Francis is distorting the truth. The Commissioner believes a large number of black cops have been inside the police force for a long time. He needs someone to infiltrate a mysterious organization to investigate the matter. But everyone on the force is suspicious and Peiyao's testimony is misleading. The police executives are very confused and cannot tell who is righteous and who is evil.