r valley began, came
vegetation. Sparse at first, then springing to luxuriant growth, it
contrasted strongly with the barren wall beside it and the equally
barren waste of high ground where the fires were.

Mountains hemmed it in; their distant peaks showed black, with red and
green striations of mineralized deposits. The valleys about them were
dense with foliage, a green so startling and vivid as almost to offend
the eye.

Trees were in the lower end of the valley. They were of tremendous
growth, and the dew of early morning dripped from them like rain.
Trunks smooth and ghostly white, except where the bark had split into
countless fractures and the scarlet color of the sap-wood showed
through. Outflung branches forked to drop down dangling stalks that
rooted again in the ground; these made a forest of slender white
supports for the leafy roof--a forest of spectral shapes in a
shadow-world. Only here and there were arrows of sunlight that
pierced the dense foliage above to strike through and down to the
black earth floor and the carpet of rainbow hues.

And that carpet of radiant colors was trampled into paths that wound
on to lose themselves in the half-light of that ghostly world.

* * * * *

From one of the paths came sounds of tramping feet. Cries and snarling
grunts resounded through the silence to send lizards scurrying to the
safety of the trees. Animal cries or hoarse voices of men--it would
have been difficult to tell which. And a sight of the creatures
themselves would have left an observer still in doubt.

A score of them, and they walked upright. Some bodies were naked, a
coppery-black in color; on others the skin was covered by a sparse
growth of hair. Noses that were mere nostril-slits; low foreheads,
retreating flatly to a tangle of matted hair; protruding jaws which
showed the white flash of canine teeth as the ape-like faces twisted
and the creatures tugged at ropes of vines thrown over their
shoulders.

The Neanderthal Man had not learned to use the wheel; and these
man-animals, too, used only the sheer strength of their corded muscles
as they hauled at the body of a beast.

It dragged along the path behind them, rolling at times to show the
white of its belly instead of the flexible armor-plating that
protected its back. Fresh blood flowed from a wound in the white
under-skin; this, and the dripping flints that tipped their spears,
told how death had come. O