herbal medicine and anthropological-archeological reasoning. The book introduces Ayla, a young girl belonging to the titular clan who looks nothing like her peers, especially with her long, golden hair. The Valley of Horses The Valley of Horses was released in September 1982. Ayla, cast out of the Clan, has been forced to follow the advice given her in the first book by her dying foster-mother Iza. She goes in search of "the Others"—that is, people like herself: European Cro-Magnon Homo sapiens, or early-modern humans, returned west and north to Europe after an incubation period of tens of millennia in the near and far east. The Mammoth Hunters The third book in the series, The Mammoth Hunters, was released in fall 1985. It details Ayla's personal growth as she learns to cope with a society of widely disparate individuals and their unpredictable behaviors, mysterious motivations, and habits. The Plains of Passage The Plains of Passage was released in November 1990. Ayla and Jondalar travel west, back to Zelandonii territory, encountering dangers from both nature and humans along the way. Her interactions often force the people around her to take a broader view and be more accepting of new ideas. The Shelters of Stone The Shelters of Stone was released on 30 April 2002. Ayla and Jondalar reach the Ninth Cave of the Zelandonii, Jondalar's home, and prepare to marry and have a child. Unfortunately, nothing is ever simple, especially for a woman with Ayla's background. The Land of Painted Caves The Land of Painted Caves, a sixth and final installment in the Earth Children's series was published on March 29, 2011. Author Jean M. Auel is quoted in September 2010 saying that in the book Ayla is now about 25 years old and training to become a spiritual leader of the Zelandonii. Her training includes a series of harrowing journeys. The setting Since the stories take place during the Würm glaciation, populations are small in number and are surviving mostly in hunter-gatherer fashion. Prior to the discovery of metals, the primary materials used for tools are leather, wood, bone, horn, and flint. People In Auel's series, two cultures vie for resources, space, and survival: the Clan, which is what Neanderthals call themselves, and the Cro-Magnons (whom Ayla, with her Clan upbringing, generally refers to as "The Others"). The races are fairly different in culture, society and technology, but with some overlap: