In Hong Kong, a shadowy group called Vendetta launches a brazen attack on the city’s education system, detonating bombs that draw intense police scrutiny. At the center of the storm is Poon Shing Fung, Andy Lau, a former Hong Kong Police Explosive Ordnance Disposal officer who lost his leg in a rescue mission five years earlier. His career was cut short by his superiors, who feared the scandal of employing a handicapped officer would taint the police, and that betrayal pushes him toward Vendetta, seeking a sense of purpose and revenge.
Four months pass, and security footage catches Poon in the act of placing a bomb at a hotel. He is knocked unconscious by the blast and wakes up with no clear memory of what happened. Interrogations fail to reveal the truth, and a hospital escape plunges him deeper into suspicion. On the trail are Pong Ling, [Ni Ni], the chief inspector of the Counter Terrorism Response Unit, and Lee Yiu-sing, Philip Keung Ho-Man as the CID Chief Inspector, who are determined to uncover Vendetta’s backers and the enigmatic figure known as Blizzard, as well as any link to a mysterious 'Davy.'
Vendetta operatives descend on the hospital to pull Poon back, but are swiftly stopped by Lee and his team. In a tense confrontation, Poon corners Pong Ling, who reminds him of his former life as an elite EOD officer, his fraught relationship with his bosses, and the sharp blow to his reputation when he was slandered at a formal ceremony. Poon is told he is Blizzard, Vendetta’s elusive operative, yet he insists his allegiance to Vendetta is a form of undercover justice—arguing that his actions are a carefully orchestrated plan to reclaim his career and expose the truth. His friend Tung Cheuk-man, Sean Lau, an EOD officer and Poon’s closest ally, is caught between loyalty and conscience as a neurologist’s memory-manipulation techniques blur the lines between truth and implanted false memories. Tung is deeply troubled, but he goes along, hoping the outcome will grant Poon mercy from the courts.
The plot thickens as Ma Sai-kwan, the Vendetta leader (played by Ma Sai Kwan) and his subordinates—codenamed Money, Slave, Sniper, and Rhino—plan another devastating strike. Sniper is dispatched to force a large-scale catastrophe, targeting critical infrastructure by poisoning gas pipelines beneath a central district. Tung, Lee, Pong Ling, and the remaining EOD veterans—Lun Ting-pong, Ron Ng Cheuk-Hai, and Chan King-to, Kenny Wong Tak-Ban—race to the scene. The ensuing firefight wounds Chan and Tung, though Tung survives thanks to his armored suit; Chan dies from his injuries despite valiant attempts to save him.
Poon’s path collides with Pong Ling again when Vendetta closes in on him at the hospital. Ma traps Poon using a mind-game inspired by a board game called Mastermind, forcing Poon to confront his true identity before he can leave. Pong and Tung reassemble a rescue squad, but the truth comes to light: Poon’s loyalty is tested as he recalls the true nature of his own past. With this revelation, Poon reveals Vendetta’s next target—the IFC building, the MTR, and the Airport Express—while “Davy” is feared to be a tiny nuclear device capable of catastrophe on a scale the city has never seen.
As the clock ticks, Lun and Fat Sze, Raymond Chiu, manage to defuse a rigged van in the IFC parking garage after a furious confrontation that leaves Money and Slave dead. Rhino’s men are eliminated in the ensuing battles, and Rhino himself ends his own life as the net tightens around Vendetta’s network. Lee’s team pushes forward to stop Ma’s assault plan, coordinating a desperate raid on multiple fronts to intercept the bombs and seize control of the situation.
With the clock running, Poon and Tung prepare a perilous gambit: plant a countermeasure near a vital location and force a final standoff. Tung escapes in a helicopter, while Poon stays behind to make amends for his earlier actions. In a tearful farewell, he chooses to sacrifice himself to derail the destruction of the Tsing Ma Bridge, tying Ma’s train to the severed bridge so it sinks and detonates away from the city’s core. The explosion triggers a submarine-like shockwave, shielding Hong Kong from a far-reaching catastrophe. Lun helps to steer the plan to completion, and Pong Ling is left crying at the enormity of what has been sacrificed, wondering if the loss was justified.
In the final scenes, Pong Ling seeks to preserve what remains of her memories, asking a neurology team to erase everything connected to Poon except a single, defining moment. A flashback reveals a quiet, telling instance from a police dinner: Poon deliberately spills a little red wine on Pong Ling’s uniform to catch her eye, a small gesture that becomes the last, lingering trace of their complicated bond. The city breathes a cautious sigh of relief as the memory fades, and Pong Ling faces the choice of moving forward without the pain of the past.
