At the year 2035, convict James Cole reluctantly volunteers to be shipped in time for you to discover the origin of a lethal virus that destroyed the majority of the earth's population and forced the survivors. But he is arrested and locked in a hospital when Cole is mistakenly sent to 1990 in the place of 1996. There he meets psychologist Dr. Kathryn Railly, also patient Jeffrey Goines, the son of a renowned virus expert, who may hold the secret to the mysterious rogue band, the Army of the 12 Monkeys, thought to be in charge of unleashing the killer disorder.