On the planet of the star Lalande 21185, known to Terrans as Ormazd, the dominant humanoid species is organized into hive societies much like those of Earth's ants and bees. In each community a hyper-fertile queen and a handful of male drones are responsible for reproduction, while all other tasks are performed by sterile female workers. This status quo is disrupted by the arrival of the "Paris", an exploratory spacecraft of the "Viagens Interplanetarias", Earth's space authority. Its mixed crew of socially equal and universally fertile males and females opens up other possibilities to the natives, and particularly to Iroedh, a scholarly worker from the community of Elham. Her own antiquarian research leads her to the conclusion that Ormazd's society may once have been like Earth's. Her peers, however, are only interested in ferreting out the Terrans' technological secrets for possible military use. Iroedh, by making friends with Winston Bloch and Barbe Dulac, two of the newcomers, ironically finds herself in a better position to do this than her more self-interested comrades.