故事发生在一个电脑科技极为发达的年代,一名科学家发明了一个杀人程序协助警方办案,其中集结了数百名连环杀手的资料和他们的作案手法。这个程序是如此的邪恶,最后不仅生成了个人意志,更拥有了人类的外表和可以随时修复任意损伤的特殊能力,它从禁锢中逃脱了出来,在世间作恶。 为了捕捉这位邪恶的“凶手”,警方设计了一个追踪仪器,罪犯帕克(丹泽尔·华盛顿 Denzel Washington 饰)被选中成为了仪器的试验品。帕克曾经亦是一名警察,却因为动用私刑杀死了让他家破人亡的杀手而被免除了职务打入大牢。而让帕克感到在意的是,在杀人程序中,亦有当年杀害他家人的那名杀手的存在。
While driving through the desert with his wife Carol Marvin to a military base to send the eleventh rocket to the orbit of Earth for helping the exploration of the outer space in the Operation Sky Hook, Dr. Russell A. Marvin and Carol see a flying saucer and accidentally records a message in their tape recorder. Once in the base, Dr. Russell is informed by his father-in-law and general that the ten first satellites had mysteriously felt on Earth. When Dr. Russell decodes the message, he encounters the aliens that ask him to schedule a meeting with the leaders of Earth in Washington in 56 days with the intention to invade Earth without panicking the population. Dr. Russell develops an anti-magnetic weapon that becomes that last hope of human race against the hostile aliens.