What has happened to man since the days when his rugged ancestors battled the mastodon and the saber-tooth tiger and wrestled a living from the raw nature of a untamed world? This was the directive that brought a dedicated group of scientists to device a means od sending one of their number back into the OLD STONE AGE when the great hunters of the Cro-Magnon days ripped the world away from the Neanderthals and their savage clan rivals