Inspired by French-Canadian director Jean-Jacques Annaud's 1981 movie Quest For Fire (a cinematographic adaptation of the novel of the same name by J.-H. Rosny aine  published in 1909), this song tells of the struggle of a prehistoric tribe to regain the fire that had been lost. The story of the book and of the film depicts the loss of the precious fire by a tribe of early hominids after a fight. They become once again lost in the middle of the land where great predators roam. One of them volunteers to go and find another fire: Quest For Fire relates his adventures.
The dawn of Mankind was no bed of roses for this poor creature that didn't have the strength, the claws or the swiftness of movement that the other animals had. The mastery of fire was his only asset and its loss was a catastrophe. The story highlights that Man's intelligence and craft allowed him to face the most difficult situations successfully. The "hero" defeats various enemies, learning each time a bit more. A nice example of Mankind's progress. In the book, the theme of decadence also appears with the mammoths, then at the heights of their power, being slower to progress than the young human species.
Many people consider this song to be the worst on the album, and they might be right, but being the worst track on an album of this calibre doesn't say much. It is rather acceptable, although it's hard to understand why dinosaurs are mentioned. There are none in the book or in the film, and according to current evolutionary understanding, humans and dinosaurs never co-existed. Perhaps we can attribute it to poetic license, since it isn't a very serious song to begin with.