The source of fire used by a clan of cavemen is extinguished during a ferocious battle with a group of Neanderthals. Not knowing how to create fire themselves, three members of the clan must go on a journey in search of fire. This trip is fraught with danger, hardship and enlightenment, as the fire-seekers have to deal with humans at many levels of advancement, as well as saber-toothed tigers, wooly mammoths and cannibals.