Robert Nathan's fantasies are becoming more and more retroactive: The Fair (1964) returned to Arthurian times and this book (""in its own odd little way, an answer to Existentialism"") spends a short time with an aboriginal tribe still leading a Stone Age existence. Osgood, an archaeologist, and Mallet, the anthropologist-diarist of the title, make an expedition to the Superstition Mountains in the Arizona desert where some two hundred People of the Bear still carry on the words and ways of ancestors born ""beyond the mists of time."" They also have preserved some puzzling artifacts-- a set of dentures, or a Goldwater button. The Professors, at first prisoners, are then requested to record the history of the tribe and they participate in their mammoth hunt, perhaps the greatest illusion of all.... Throughout, even if Nathan is no match for Sartre, he engages in gentle cosmic speculations about the enigma of existence in this ""incomprehensible"" world and the validity of the past in an unruly present. There are also, expectedly, patches of pretty prose.