James Cole, a state prisoner in 2035, can gain release if he agrees to return back in time and stop a deadly plague. The virus has wiped out the majority of the Earth’s population, and the remaining survivors are forced to dwell underground due to the poisonous air. Returning to 1990, six years before the outbreak, Cole is quickly imprisoned in a psychiatric institute since his warnings sound like insane rants. There he meets Dr. Kathryn Railly, a scientist, and Jeffrey Goines, the insane son of a virologist. Cole is returned to the year 2035 by the authorities, and eventually arrives at his planned location in 1996. He kidnaps Dr. Railly to enlist her assistance in his quest. Cole discovers graffiti by an alleged animal rights organization called the Army of the Twelve Monkeys, but as he explores deeper into the mystery, he hears voices, loses his bearings, and begins to doubt his own sanity. He must determine whether Goines, who appears to be a raving madman, possesses the key to the problem.