Astronomer Harry Malibert is at an airport when nuclear war breaks out. Having been recognised by a fan, he is offered a seat on a plane to Iceland. Though most of Reykjavik has been destroyed by a thermonuclear weapon, the rest of the Iceland has been left untouched. Malibert and the remaining survivors must take advantage of Iceland's geology in preparing for the nuclear winter ahead of them, all the while calculating their chances of survival and contemplating the Fermi paradox: given the size and age of the universe, there ought to be many extraterrestrial civilisations, yet none has so far been found. Will Malibert and his group survive, and will they or their successors live to see proof of extraterrestrial civilisation?
Pohl and Kornbluth started writing together as early as 1940, although both authors produced a wide variety of stories separately, under their own names and psuedonyms. Each wrote sections, starting where the other left off, and through long experience they developed an almost telepathic awareness of each other's intentions.