Twenty thousand years ago in prehistoric Siberia a young girl named Yandan lived and died. Now, as a spirit, she tells the story of her life, a continuous struggle to survive. A noted anthropologist, the author is very concerned with describing the relationship between human and animal. Thus, in Reindeer Moon people take a back seat to nature. Just as the reader is engrossed in one of Yandan's life experiences, the scene shifts to an account of one of Yandan's spirit journeys, a confusing device, and one that detracts from both storylines. Comparisons between Reindeer Moon and Clan of the Cave Bear ( LJ 9/1/80) are bound to arise. Like Jean Auel, Thomas has a difficult time making prehistoric sex anything but laughable. Reindeer Moon lacks the "popular touch" that makes Auel's books best sellers; yet readers interested in the period and with an eye to nature might enjoy this. Lydia Burruel Johnson, Mesa P.L., Ariz.