The Valley of Horses, the second book in Jean M. Auel's Earth's Children series, follows the journey of Ayla, a young woman who has been raised by the Clan, a group of Neanderthals. Ayla is determined to find the people of her own kind, the Cro-Magnon. This book picks up after Ayla has been separated from the Clan and she must survive on her own. It shows the importance of learning to survive and the importance of the bond between Ayla and her new companion, a wild horse.