The brothers Chow Nunn and Chow Lui's giant computer company is facing a tense crisis - a powerful computer virus is rapidly wiping out their computer network. At the last minute a cyber-friend arrives to join the battle. The mysterious - Angel.com - battles the virus and saves the company. Invited by Chow Lui for a visit in person, Angel.com arrives in the form of the beautiful Lynn (Shu Qi). But it turns out Lynn is a professional assassin with amazing high-tech and kung fu skills. She kills Chow Lui with cyanide hidden in a pair of sunglasses. She's aided by her sister Sue (Zhao Wei), who operates the pair's World Panorama surveillance system, which allows them to tap into any video security system in the world. Young cop Kong Yat Hong (Karen Mok) and her partner Mark are put on the case. Hong has a brilliant mind and immediately senses she's dealing with a killer with very special skills. Realizing they are facing a tough adversary, Lynn and Sue become fascinated with Hong as well...