It is a direct sequel to the first novel in the series, Expendable, in that it picks up the dual story of Festina Ramos, Explorer turned admiral, and the transparent glass woman Oar, where the earlier novel left off.

At first only the most disadvantaged and unhappy members of human society take the Shaddill up on their offer; but when they return to visit Earth in a year or two with tales of their wonderful new lives, the exodus increases— which causes more and more problems for those who remain behind.

By the time the Shaddill's 20-year offer expires, the only people left on Old Earth are those too stubborn or violent to make the leap to a new society, and who must subsist in the collapsed remains of the old.

At the end of Expendable, Festina left the apparently deceased Oar lying in one of the Towers of Ancestors on her planet, where her people absorb high-energy radiations that sustain their lives.

This is Uclodda Unorr, a professional smuggler who has been hired to gather evidence on past misdeeds of the Technocracy's Outward Fleet—and who is surprised to discover that Oar is alive.

Oar triumphs over her adversaries, and also fulfills her bargain with the Pollisand, who in turn presents her with a remedy for the "Tired Brain" syndrome that leaves her people comatose in the Towers of Ancestors.