The second tier of humans, referred to as Betas, are "normal" humans that were initially created by the Kontrin from human eggs, programmed to be loyal to the Kontrin, and then allowed to breed amongst themselves. Cherryh's Azi race of human clones make up the third tier, acting as servants or slaves to the Kontrin, the Betas and also the Majat. Although it is primarily an "Alliance-side" novel (not Union), the story nevertheless features Azi because Union settlers originally colonized the Hydri stars.