Hackers release a virus onto the web and unleash a large-scale cyber attack. Fortunately, cyber security engineer and IT whiz, Cheuk Ka-Chun, uses a firewall he developed to resolve the crisis. Unbeknownst to Ka-Chun, the mastermind behind this virus is his superior, Chan Ming-Chi. As the two begin to butt heads, Ka-Chun secretly develops a rival virus and Ming-Chi plots to have Ka-Chun`s wife and daughter kidnapped. As Ka-Chun panics, his new virus starts to spread across every computer in Hong Kong – threatening the entire city`s future.