The film describes the events leading up to, and including, the massacre of the adults of a small town in Nebraska by their children, after the adults' irresponsibility ruins the crop and the children's future.

In a futuristic world, a strict regime has eliminated war by suppressing emotions: books, art and music are strictly forbidden and feeling is a crime punishable by death. Cleric John Preston (Bale) is a top ranking government agent responsible for destroying those who resist the rules. When he misses a dose of Prozium, a mind-altering drug that hinders emotion, Preston, who has been trained to enforce the strict laws of the new regime, suddenly becomes the only person capable of overthrowing it.

Set in the late 21st century, a subculture of humans have emerged who have been modified genetically by a vampire-like disease, giving them enhanced speed, incredible stamina and acute intelligence, and as they are set apart from "normal" and "healthy" humans, the world is pushed to the brink of worldwide civil war aimed at the destruction of the "diseased" population. In the middle of this crossed-fire is - an infected beautiful woman - Ultraviolet, who finds herself protecting a nine-year-old...