In 1962, Dr. Calvin Webber (Christopher Walken), an eccentric scientist who like so many people at the time, thinks that a nuclear war between the U.S. and the Soviet Union is imminent. He has built a large, fully functional fallout shelter in his backyard deep underground. During the Cuban Missile Crisis and thinking the conflict could escalate, Calvin ends the party at his house and takes his pregnant wife Helen (Sissy Spacek) into the fallout shelter as a precaution. When a fighter jet flying over loses control, the pilot bails out and the jet crashes into their house, causing a large explosion; Calvin, thinking the worst has happened, sets and activates the shelter's locks (designed not to open for 35 years). Everyone assumes the entire family was killed in the accident, as no one knew of Calvin's secret fallout shelter.