With their culture coming apart at the seams, and extinction from feral reversion threatening their species, the Lindauzi believe they have finally found success and salvation in Ilox, a human boy with great emotional sensitivity.
As the novel opens, the Lindauzi are reeling from the extinction of their soul-mate species, the Iani, without whom they will lose all sense of themselves and succumb to "reversion," a return to a feral, animal state.
Ilox is the pinnacle of the breeding program, an exceptionally bright and empathic human boy who at an early age can sense the presence and emotions of nearby Lindauzi.
Ilox eventually adapts to life among the free humans in the settlement of Jackson, and takes a wife, Mary, with whom he has two sons, Caleb and Davy.
Phlarx agrees to take Caleb and Ilox to the "Summer Country" - South America - where it is too warm for Lindauzi to settle and humans live with relatively little interference.
He arranges for the air filters in the forcefields surrounding the Lindauzi cities to be altered so that carbon monoxide emissions will slowly reach lethal levels, leading to a peaceful and dignified death for his species.
Caleb adapts well to life among the human population of the Summer Country, and Ilox slowly begins regaining his senses, though he never recovers them completely.
He has recurring prophetic dreams about the death of all the Lindauzi, which the humans of the Summer Country decide to act on, making tentative exploratory forays beyond their safe haven in the tropics.