In the splendid Beggars in Spain (1993), Kress invented a breed of humans who no longer needed to sleep--a compelling idea that the disappointing Beggars and Choosers (1994) dissipated in ho-hum nanotechnology and political manipulation. Here, clearly bored with the whole notion of sleeplessness, Kress meditates gloomily on the horrid but obvious consequences of genetic engineering driven by malevolence. While gene-modified ``donkeys'' cluster in their sanitized enclaves, the supply of health-giving Change syringes gives out, so the ``Liver'' masses can't keep their children healthy and decline into squalor. Caught up in the struggle between the two groups, donkey doctor Jackson Aranow also becomes aware of the bitter rivalry between the Sleepless and the bioengineered descendants, the SuperSleepless. Paranoid, immortal Jennifer Sharifi and her fellow-Sleepless, determined to make themselves utterly secure, commission a donkey genetics whiz to create a virus that will render Livers and donkeys alike fearful of confronting anything new. Meanwhile, Jennifer's daughter, Miranda, and her SuperSleepless, paralyzed by indecision, are no longer producing Change syringes and, stupidly, disregard the threat posed by mad Jennifer. So Jennifer blasts Miranda with a nuclear missile, only to get blasted in turn by vengeful donkeys. Dreary and annoyingly, sophomorically didactic, though fans of the previous two volumes will probably want to investigate.