The novel tells about an artificially created race of bixes (bio-cybernetic systems), outwardly no different from humans. By that time, some people will leave our planet, and the rest of humanity will enter into conflict with the Bix, in the center of which will be Bron Pitirim Brion, the scion of an elite family. Due to a combination of circumstances, he has to betray his own kind, experience strange, unrequited love, and participate in the Great Exodus of the Byxes - a kind of bloodless massacre committed by his fellow tribesmen.