Rachel is a divorced single mom whose unhealthy day will get even worse. She's operating late to drop her son off at college when she honks her horn impatiently at a fellow driver throughout rush-hour site visitors. After an trade of phrases, she quickly realizes that the mysterious man is following her and her younger son in his truck. A case of street rage shortly escalates, at horrifyingly psychotic proportions, into full-blown terror as Rachel discovers the psychopath's sinister plan for revenge. He's single-mindedly decided to show her a lethal lesson.
