The wrap-up to Hinz's futuristic trilogy about a power struggle between a repressed humanity and the Paratwa, telepathically linked pairs of talented beings supported by a mysterious royal caste. Like Ash Ock (1989), this one's not independently intelligible. The human race, which survives only in the Irryan space colonies, faces invasion by hordes of Os/Ka/Loq, mind-linked aliens who secretly created the Paratwa and now covet the (presently uninhabitable) Earth. The warrior Paratwa, Gillian, gains a new tway (partner), Susan, and learns the truth behind the Ash Ock. Dwarf computer-whiz Nick and his human allies ponder how the Os/Ka/Loq and their Ash Ock representatives can be driven away despite their warriors and advanced science: If the humans nuke and poison Earth's recovering biosphere beyond even the Os/Ka/Loq's ability to resuscitate, the aliens would have no reason to hang around, and might even agree to let humanity survive. Imaginative and fairly well handled, overall, though decidedly too self-involved. Hinz offers enough plot twists and action here to satisfy the faithful, though newcomers will have to start all the way back at book one.