Updated: July 18, 2026

Harriman Nelson ( Walter Pidgeon ) is the creator of a revolutionary nuclear submarine. After testing its capabilities in the Arctic Ocean, Nelson and the commanding officer ( Robert Sterling ) surface the vessel, only to discover the sky ablaze. Learning that the Van Allen radiation belt has caught fire, Nelson conceives a plan that could save the planet from destruction, but the U.N. shoots it down. Nelson is convinced it will work, but an onboard psychiatrist ( Joan Fontaine ) questions his sanity.