The authenticity of background detail, the lilting prose rhythms and the appealing conceptual audacity that won many fans for The Clan of the Cave Bear and The Valley of the Horses continue to work their spell in this third installment of Auel's projected six-volume Earth's Children saga set in Ice Age Europe. The heroine, 18-year-old Ayla, cursed and pronounced dead by the "flathead" clan that reared her, now takes her chances with the mammoth-hunting Mamutoi, attended by her faithful lover, Jondalar. Gradually overcoming the prejudice aroused by her flathead connection, Ayla wins acceptance into the new clan through her powers as a healer, her shamanistic potential, her skill with spear and slingshot and her way with animals (she rides a horse, domesticates a wolf cub, both "firsts," it would seem, and even rides a lion). She also wins the heart of a bone-carving artist of "sparkling wit" (not much in evidence), which forces her to make a painful choice between the curiously complaisant Jondalar, her first instructor in love's delights, and this more charismatic fellow. The story is lyric rather than dramatic, and Ayla and her lovers are projections of a romantic rather than a historical imagination, but readers caught up in the charm of Auel's story probably won't care. 750,000 first printing; $300,000 ad/promo; paperback rights to Bantam; Literary Guild and Doubleday Book Club dual main selections; author tour.