Dark Universe was the first—and most popular novel—of New Orleans journalist Daniel F. Galouye, although he had been publishing magazine stories since 1952. It was nominated for a Hugo Award.
The story is seen—or, rather, heard—by young Jared Fenton, whose primitive people live in total darkness and think of Light as a dimly remembered religious deity. They are preyed on by zivvers, other underground humans whose eyes have adapted to provide limited sight in the infrared spectrum, and “monsters” that inspire fear because they cause people to disappear and because they use light, which is alien to Jared’s people.
Jared is the son of his tribe’s ruler, the Prime Survivor. He is pressured into an arranged marriage (or “unification”) with Della, the niece of another tribe’s leader, to unite the tribes against the zivvers. Della has developed the zivver ability and, because Jared is exceptionally gifted at sensing people or objects by vibrations from sound echoes, believes he is secretly a zivver also. She persuades him to flee with her to the zivver group, which Jared has been seeking for his own reasons: He believes that Light is a natural phenomenon and that he might learn its nature through the zivvers.
Eventually, the young couple become outcasts and fugitives from both groups. Jared’s people also decide that he is a zivver and therefore an enemy. The zivvers test him and discover that he is not one of them. He and Della fall into the hands of the monsters, who are revealed to be descendants of survivors from underground shelters who are now reinhabiting Earth’s surface, which has purified itself. The two tribes and the zivvers from Jared’s underground world had also sprung from a survival group, but something had gone wrong in their complex. They had lost their artificial light and, gradually, all knowledge of their origins. The monsters had been kidnapping them, a few at a time, and reeducating them.
Still not fully understanding or accepting the explanation, Jared escapes and makes his way to the surface. He realizes the truth of what he has been told and looks forward to a new life in a new world with Della.