亚洲电脑业巨头周氏兄弟发现其公司内部的电脑系统于一夜之间感染病毒全部瘫痪,四处求救之时,一个自称“天使”的神秘高手出手相助,麻烦成功解除,令周氏兄弟十分钦佩。出于好奇,他们提出与“天使”见面道谢,不想应约而至的“天使”是一对拥有天使面容的姊妹花——陈爱琳(舒淇)和陈爱群(赵薇),而之前的电脑中毒事件,也是由这对姊妹花一手策划:她们是想借此突破周氏公司森严的保安系统,实施更大的阴谋。 女警江日红(莫文蔚)闻得风声,在爱琳和爱群实施阴谋时展开调查,不想仍让她们得手。随后,在周氏兄弟的策划下,爱琳死于乱枪之下,可是现场留下的指纹却是江日红的。无奈之下,江日红与爱群联起手来,两人逐渐由敌手变作朋友。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. 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, 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 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. Lynn runs into Yan, the cousin of an old friend who died. Lynn and Yan shared an unspoken love in the past which is now rekindled in the open, and Lynn begins to question whether she wants to continue to be an assassin. Chow Nunn was behind his older brother's death. He hired Angel.com to kill Lui because Lui opposed Nunn's business plans, and also because Nunn is carrying on a secret affair with Lui's wife. But when Hong's investigation starts to point to Nunn, Nunn becomes worried and decides to hire Angel.com for another hit ^Ö only so he can double-cross them, wipe them out and prevent them from leading the police back to him. Yan tells Lynn he loves her and wants to marry her. After battling an attack by robbers with her amazing martial arts skills, she tells Yan her family's history. Her father invented the World Panorama for use by the authorities, but was turned down. Suspiciously, word of the device got out to the underworld and both parents were brutally killed in front of the girls' eyes by criminals eager to get their hands on the invention. Bereft at the loss of their parents and disillusioned with the law, the sisters turned professional assassins, killing criminals for other criminals. Lynn tells Sue she wants to stop their criminal life and get married ^Ö she won't accept Chow Nunn's order for the second killing. But Sue, angry and feeling abandoned by Lynn, decides to carry out the killing herself. Lynn realizes what's happening and rushes to save Sue, who doesn't have the skills to carry out the hit. They are attacked by Chow's men but escape. Now the assassin and the cop must join forces - so Sue can avenge her sister's death and Hong can prove her innocence in a spectacular confrontation at Chow Nunn's headquarters...