In 1970s Hong Kong, the Independent Commission Against Corruption (ICAC) was formed to bring down the corruption syndicate led by British government officials. One of its top investigators is Senior Investigator Lau Kai-Yuen, who brought down countless corrupted officials. Just as he thought stability and prosperity are within reach, a new era of greed and riches takes him into a new battlefield of corruption.
After suffering life changing injuries in the line of duty, bomb disposal officer Fung turns his back on the police. But when a devastating series of bombings sweep Hong Kong, the police suspect their former ally may be involved after he is found unconscious at a crime scene. Now faced with memory loss and recalling only fragments of his former life, Fung sets out to uncover the truth and find out who he really is.
Hong Kong Customs and Excise Department officers Chow Ching-lai and Cheung Wan-nam share a close mentor-student relationship. On a case involving seized smuggled arms, Ching-lai is sent to take part in a joint operation with Interpol to capture a reclusive arms dealer. However, Wan-nam makes a drastic decision that further complicates the case.
Cheung Sung-bong is a highly respected cop with a long history of success in dangerous cases. However, his past soon comes back to haunt him when a former protégé resurfaces, seeking revenge.
A vigilante serial killer in Hong Kong leaves ominous death notices, prompting the police to launch a special task force to uncover a hidden conspiracy.
Ho Sau, an undercover agent, has been working with Yau, a drug lord, for years, but his job and family are in trouble.
A chief inspector in the anti-narcotics unit holds true to his beliefs as a police officer. He puts everything on the line to crack down on drugs and to bring drug traffickers to justice. How will our hero resolve this "bursting point" crisis?
