Nine thousand years ago, five clans lived in caves on a tree-covered escarpment overlooking the great northern European plain. Unlike today, man's imprint on Planet Earth was minuscule and as a result, animal life blossomed on land, in the sea and in the air. Despite this bountiful planet, life for these Stone Age clans was short. In their verbal history spanning many generations, the clans had never encountered other people. Over fires in the evenings, some said that there must be other people; others said that they were alone. The latter were proven wrong.