Light years separate Thomas's intelligent, literate fiction from most other novels set in prehistoric times. Exuding authenticity and distinguished by resonant language, this novel, a companion to Reindeer Moon, is likewise set in the savannastet of the Siberian Paleolithic. The narrator, Kori, and his hunter-gatherer people are portrayed as heroic but also fallible, sometimes prey to bad judgment and overwhelming passions. Kori is beset by guilt...