oo many such
wrecks to be found. What do you think this planet was, a flypaper to
attract them?"

"But if ships crashed here once, why didn't they later when men were
better able to understand them?" Ross countered.

"For several reasons--all of them possible and able to be fitted into
the fabric of history as we know it on this world. Civilizations rise,
exist, and fall, each taking with it into the limbo of forgotten things
some of the discoveries which made it great. How did the Indian
civilizations of the New World learn to harden gold into a useable point
for a cutting weapon? What was the secret of building possessed by the
ancient Egyptians? Today you will find plenty of men to argue these
problems and half a hundred others.

"The Egyptians once had a well-traveled trade route to India. Bronze Age
traders opened up roads down into Africa. The Romans knew China. Then
came an end to each of these empires, and those trade routes were
forgotten. To our European ancestors of the Middle Ages, China was
almost a legend, and the fact that the Egyptians had successfully sailed
around the Cape of Good Hope was unknown. Suppose our space voyagers
represented some star-born confederacy or empire which lived, rose to
its highest point, and fell again into planet-bound barbarism all before
the first of our species painted pictures on a cave wall?

"Or take it that this world was an unlucky reef on which too many ships
and cargoes were lost, so that our whole solar system was posted, and
skippers of star ships thereafter avoided it? Or they might even have
had some rule that when a planet developed a primitive race of its own,
it was to be left strictly alone until it discovered space flight for
itself."

"Yes." Every one of Ashe's suppositions made good sense, and Ross was
able to believe them. It was easier to think that both Furry-face and
Baldy were inhabitants of another world than to think their kind existed
on this planet before his own species was born. "But how did the Reds
locate that ship?"

"Unless that information is on the tapes we were able to bring along, we
shall probably never know," Ashe said drowsily. "I might make one
guess--the Reds have been making an all-out effort for the past hundred
years to open up Siberia. In some sections of that huge country there
have been great climatic changes almost overnight in the far past.
Mammoths have been discovered frozen in the ice with half-digested
tropical p