Forced to leave the Clan, and her young son, Ayla sets out alone to travel the frigid steppes until she finds the valley of horses. Unable to find people like herself, the Cro Magnons, she settles there and seeks friendship elsewhere. First she adopts a young filly, then a wounded lion cub.

But far to the west, two young Cro Magnon brothers have begun a journey. One of them is Jondalar, whose destiny is bound inextricably with Ayla's.

Jean Auel's imaginative reconstruction of pre-historic life, rich in detail of language, culture, myth and ritual, has become a set text in schools and colleges around the world.