Elma York, a mathematician and former WASP pilot, and her husband Nathaniel, a scientist who worked on the Manhattan Project and later NACA, survive the catastrophe.

A miniature Ice Age will be followed by a sharp increase in temperature due to the greenhouse effect, ending in boiling oceans and the extinction of life on Earth.

Elma and Nathaniel present the issue to President Brannan; the UN and USA agree to begin a space colony program.

She is opposed by astronaut Stetson Parker and Director Norman Clemons, who believe that women do not belong in space.

Parker and Elma form an uneasy truce; he threatens to reveal her use of Miltown if she does not help him hide a leg injury that would keep him grounded.

[5] Publishers Weekly considered it "outstanding," with Elma's personal life "provid(ing) a captivating human center to the apocalyptic background.