Part I of The Saga of Pliocene Exile (a concluding volume, The Golden Torc, is promised), these are the patchy, verbose, moderately diverting adventures of a group of social malcontents exiled via a one-way timewarp to Earth's Pliocene epoch. They arrive (after a tedious hundred-page introduction) to find that a powerful but decadent alien race with paranormal abilities, the Tanu, have local politics pretty well sewn up: they easily enslave all the unsuspecting newcomers, the women becoming Tanu breeders, the men serfs or lordlings in a feudal economy. Another genetically similar alien race, the Firvulag, and a few humans, the Lowlifes, have evaded Tanu control and survive in a hole-in-corner fashion. Then, however, some of the group, escaping from the Tanu's clutches, meet up with Madame Guderian--who has persuaded the Lowlifes and Firvulag into an uneasy alliance (as part of a master plan to defeat the Tanu) and now packs the group off on a perilous quest to seek out ancient weapons and machines. And there's a final bloody battle as the alliance attacks the chief Tanu city to complete phase one of Mme. Guderian's plan. Generously woven, with numerous subplots involving other members of the group--but May, author of several science books for children, maddeningly obscures his captivating and singular Pliocene backdrop with a lot of perfectly ordinary sword & sorcery razzle-dazzle. So: only those readers partial to comfortably middleweight, myth-oriented fantasy (and willing to plow doggedly through the duller stretches) will be entertained enough to come back for more.