"No, the Saurons were careful to stop short of complete annihilation, not because they had a system of ethics, but because they needed the survivors. Needed slaves to construct the enormous citadel-like fortresses within which a new generation of Saurons would hatch, each killing its progenitor during the birth process, and each taking its place within the complex racial hierarchy upon which the alien culture had been built. A social structure in which each caste had a distinct function: The Zin governed, the Kan fought, and the Fon performed menial work, or would have performed menial work had it not been for the diminutive Ra 'Na, a slave race upon which the aliens were heavily dependent. A relationship which over hundreds of years had become so entrenched that something approaching a symbiotic relationship had evolved. A reality that helped explain why many of the whip-wielding Fon overseers carried Ra 'Na technicians on their chitin-covered backs even as they forced thousands of humans to ascend Hell Hill."