United Kingdom. In an undetermined future, Alex is the leader of a gang of «droogs» who walks the streets of London cultivating his sole two passions: ultraviolence and Beethoven's music. He and his young followers vent their most violent instincts on any person crossing their path. They beat, rape and terrorize their victims. When their escalation of terror culminates in murder, Alex is arrested and sent to prison. There he volunteers for an ground-breaking re-education experiment aimed at drastically eliminating in convicts the slightest trace of an antisocial conduct.