To escape [from the anxieties of modern life, Zan, the heroine in Saturday, the Twelfth of October,] fantasizes a world in the Stone Age, complete with a new language and primitive culture. Zan gradually becomes accustomed to her new life in this primitive world, and the adventures which emerge from this unexplained time jump provide a fascinating and completely believable story within a story. Mazer never lets readers know for sure whether Zan's experience is real or schizophrenic escape, and the characters are developed with skill and understanding in both the primitive society and Zan's everyday world. An intriguing and compelling mixture of science fiction and fantasy.