When the nuclear attack defense siren at a suburban elementary school sounds-and won't shut down-the agonizing principal (William Daniels) makes the call of having his staff shepherd groups of children back to their homes. As the adults wrestle with whether the danger is genuine, the kids are left to make their own responses-some with tragic consequence. Frank Perry's long-sought, fact-inspired Cold War cautionary tale also stars Nancy Marchand, Estelle Parsons, Jane Connell. 82 min. Widescreen; Soundtrack: English; Subtitles: English; theatrical teaser.