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.
When a terrorist who specializes in explosives takes hold of an underground tunnel, he threatens to kill hostages if his demands are not met.
Wanted criminal "Helios" and his assistant stole a quantity of uranium and plan to produce weapons of mass destruction. They are planning to trade with a terrorist organization in Hong Kong. Chief Inspector Lee Yinming and Inspector Fan Kaming lead the Counter Terrorism Response Unit of the Hong Kong Police Force. Along with a Chinese senior official, a physics professor, and two South Korean weapon experts, they hope to defuse a crisis sufficient to destroy the world.
Kung and Kin's rivalry goes way back to the seventies when they fought over the same girl, who eventually became Kung's wife. Now they run competing phone stores right across from each other on Mongkok's busiest street, and stretch their minds trying to outdo each other with crazy promotions.