In Hong Kong, a vigilante killer known only as Darker dispenses his own brand of justice by issuing death notices that predict the time and method of his next murder. He strikes with brutal efficiency, and even when a victim reports the threat and gains police protection, Darker breaches those defenses and carries out the killing anyway. The city is gripped by fear as the killings unfold with an almost ritual precision, challenging the limits of the police and the public’s trust in safety.
Ten years earlier, Darker orchestrated a catastrophic explosion that tore through Man Wah, the girlfriend of police inspector Law Fei [Julian Cheung Chi-Lam], and Yeung Tsz Bong, a former senior CIB inspector and Law’s close friend. The only living witness to the disaster is Wong Siu Ping [Louis Koo], a homeless man whose face was burned and whose life was upended by the event. The survivor’s testimony haunts the case, and the memory of that explosion becomes a compass for the present crisis as Darker resurfaces with fresh, meticulously planned executions that push the police toward a hidden, far-reaching conspiracy.
In response, a dedicated task force is forged, led by Chief Superintendent Hon Ho [Francis Ng Chun-Yu]. Law Fei joins the team, bringing his sharp eye for detail and a stubborn belief that patterns can be deciphered. The investigators pair up with Wong to glean clues, but every operation seems to miss the mark, leaving victims unprotected and the killer steps ahead. Law’s ability to anticipate Darker’s moves grows sharper, yet each prediction arrives too late to stop the next tragedy.
As the hits continue, Darker’s true identity begins to emerge through a tangled web of secrets. Tensions flare between Law and Hon after Hon Siu Hung [Charmaine Sheh Sze-Man], a politician with influence, is killed in a van explosion despite police protection. The case grows colder as a third target, Pang Kwong Fook [Philip Keung Ho-Man], a suspect tied to Hon’s partner’s death and Wan Kim’s brother, falls into the crosshairs. When Pang’s location is finally located, the team disarms a bomb, but Pang’s throat is slit and the bomb reactivates, forcing a desperate retreat. Law is briefly arrested but is released with support from Leung Yam [Chrissie Chau], the one who believes in his innocence.
The investigation shifts toward a fourth target, Tang Wah [Ray Lui], a businessman who is preparing to leave Hong Kong for safety. Law interrogates Wong again and pieces together a troubling truth: the real Wong is dead, and Scar Seven—Yeung’s most trusted informer—has been impersonating him to carry out the assassination plot against Tang. Law fights to stop Scar Seven, and the airport pursuit reveals another chilling twist: Yeung is alive, having altered his appearance through plastic surgery. Yeung had engineered the warehouse explosion to derail Man Wah and to assume Wong’s identity, using that deception to eliminate rivals in a scheme tied to a powerful real estate developer. Man Wah’s own actions later sabotage Yeung’s plan, and Law manages to thwart the final stage of the conspiracy, though Yeung is left to face the consequences.
With Tang’s safety secured, Hon confronts a new form of danger: Darker slams Hon with a blackmail video showing that Hon had slit Pang’s throat during the bomb detonation. Seizing on the pressure, Darker’s call reaches Hon, who, fuelled by fear, shoots at Tang—mistakenly believing he is addressing Darker. Hon is arrested as a suspect, and the case advances toward a courtroom confrontation.
In the courtroom, Law reveals a troubling truth about Hon: the earlier testimony claiming that Pang shot Chiu was a misdirection, and Hon had accidentally killed Chiu while pursuing Pang’s partner. Hon, desperate to protect his own secret, admits nothing, but Wan—Pang’s sister and a victim’s ally—confronts Hon with the consequences of his actions. The film closes with Law’s uneasy conclusion that Hon and Darker aren’t so different in their willingness to blur lines for what they believe is justice, and it is revealed that Hon Ho and Yeung Chi Bong have been charged for their crimes, while the elusive Darker remains at large, a shadow still haunting the city.
