Beggars and Choosers.

Nancy Kress's Beggars and Choosers (Tor Books, $22.95, 320 pp.) is a vastly different novel, except that it shares - for me, anyhow - an exhilarating goodwill and joy of invention. Kress invents a twenty-second-century world in which genetic engineering and high tech have made America both affluent and class-stratified, and in which the high-functioning, trans-human mutants - the Sleepless - are involved in a scheme which aims either at the destruction or the salvation of the human race altogether. Obviously Kress, like all fine s-f writers, is talking not about the future but about the current awful state of affairs in class-ridden America. And her novel, rich and splendidly told, is both an apocalypse and a mitzvah, an assertion about the ineradicable goodness of people that reminds me of what s-f at its best - as in H.G. Wells - can be.