公元2035年，人类被12只猴子军研制的一种病毒侵袭，大部分人类都在这场病毒灾难中死亡，只有少数人侥幸逃生，但也只能在阴暗的地下，苟且偷生。 　　科学家们决定派人穿越时光回到1996年追查12只猴子军的来历。囚徒詹姆斯·科尔(布鲁斯·威利斯 Bruce Willis 饰)被 挑选为志愿者。阴差阳错，科尔回到了1990年，当他向当时的人们描述未来的那场大灾难时，被当作精神病捉了起来并被医生凯瑟琳·雪莉（玛德琳·斯通 Madeleine Stowe 饰）诊断为精神分裂症。科尔在病友杰弗里·戈因斯帮助下逃脱，回到了未来。因为没查清12只猴子军的来历，科尔再次被派回了1996年。 　　科尔这次发现了12只猴子军的起源地在费城，他找到了医生凯瑟琳，二人一起展开了追查12只猴子军的冒险之旅!An unknown and lethal virus has wiped out five billion people in 1996. Only 1% of the population has survived by the year 2035, and is forced to live underground. A convict (James Cole) reluctantly volunteers to be sent back in time to 1996 to gather information about the origin of the epidemic (who he's told was spread by a mysterious "Army of the Twelve Monkeys") and locate the virus before it mutates so that scientists can study it. Unfortunately Cole is mistakenly sent to 1990, six years earlier than expected, and is arrested and locked up in a mental institution, where he meets Dr. Kathryn Railly, a psychiatrist, and Jeffrey Goines, the insane son of a famous scientist and virus expert.