Musician Harry Washello (Anthony Edwards) sits down at a Los Angeles diner, where he instantly takes an interest in waitress Julie Peters (Mare Winningham). The feeling is mutual, too, so the pair arranges a date for later that day. But things go awry when Harry picks up a random pay phone call from a frantic soldier who warns of a nuclear attack that will hit L.A. within the hour. Scrambling, Harry finds Julie and the two do everything they can to escape to safety.