Clash of the Cavemen explores the long period in Europe when two human species - Neanderthals and modern humans called Cro-Magnons - co-existed. The special follows two human families - Neanderthals and Cro-Magnons - through a harsh Ice Age winter, as they compete for food, shelter and survival. These fictional characters are supported by the latest factual revelations coming from the ground and the lab about these mysterious people who lived at a defining juncture in human history.