This movie covers the final hour leading up to the Columbine High Massacre. On April 20, 1999, two boys from Columbine High School in Colorado embarked on a massacre and killed 12 students, one teacher, and injured 21 other students, before turning the guns on themselves.

Zero Hour dramatizes the hour leading up to some of the most memorable historical events as they unfold minute by minute. Using a real-time clock and a split screen to follow key players, the series reveals the compelling and exciting minutes leading up to events that changed the world.