First Lieutenant Jake Tanner (Jan-Michael Vincent) shares ICBM silo duty at an United States Air Force missile base in the Californian desert with Major Eugene "Sam" Denton (George Peppard), who is requesting not to work with him. On their way to duty, Denton talks to Sergeant Tom Keegan (Paul Winfield), an aspiring artist. When the United States detects incoming nuclear missiles from the Soviet Union, Tanner and Denton launch part of the Second strike. The United States is hit hard, although it manages to intercept 40% of the Soviet missiles.