A portable nuclear device, DC8, has been stolen from South Korea by a ruthless criminal (Chang Chen) and his accomplice (Janice Man). As the weapon will change hands in Hong Kong, Lee (Nick Cheung) from the territory's Counter Terrorism Response Unit sets up a task force, which includes police officer Fan (Shawn Yue), to deal with the crisis. He enlists physics professor Siu (Jacky Cheung) as an adviser and has to work with South Korean weapon experts Choi (Ji Jin Hee) and Pok (Choi Si Won). Despite their efforts, the elusive criminal mastermind, Helios, is always a step ahead of Lee.