In Hong Kong, a mysterious terrorist organization, Vendetta, run by Ma Sai-kwan (codename Maverick) and a mysterious individual known as Blizzard, bombs the region’s education bureau, making it the center of the police’s attention. Poon Sing-fung, Ma’s friend and a former Hong Kong Police Explosive Ordinance disposal officer who lost his leg to a neglected explosive in a rescue mission five years ago, was denied of his career by his superiors in fear of damaging the police’ reputation for employing the handicapped.
Enraged by their blatant betrayal, he joined Vendetta. Four months later, he is spotted placing a bomb at a hotel by security. Poon is unconscious after the bomb explodes and is now a suspect. He wakes up in a hospital with no memory about what happened, and escapes during an interrogation. Pong Ling, chief inspector of the Counter Terrorism Response Unit, and Lee Yiu-sing, CID Chief Inspector, are assigned to find out who is behind the bombings and the identity of the Blizzard and their supposedly meeting with an individual known as “Davy”. Vendetta operatives are sent to the hospital to retrieve Poon but are killed by Lee.
Poon corners Pong Ling after the chaos. She reminds him of his past life after his leg loss, such as being a model officer in the Explosive Ordnance Disposal Bureau (EODB), his deteriorating relationship with his superiors, and his slandering of the police forces in a ceremony honoring him. Poon is also told he is the Vendetta member Blizzard. While most of this is true, Pong claims that he joined Vendetta undercover to stop them and reclaim his career. Pong tells Tung Cheuk-man, another EOD officer and Poon’s best friend, that when Poon fell into a coma, she hired top neurology doctors to manipulate his allegiance via implanting false memories. Tung is upset with their methods and only plays along as Poon’s friend. Pong retorts that this is the best way for the HK supreme court to show Poon mercy after his involvement in the bombings.