learned. It now looked as
if Venus and Mars trips were still a dozen years away.

Burl Denning was keenly interested in all of this. As a senior in high
school, the newly expanding frontiers of the universe represented
something special to his generation. It would be men of his own age who
would eventually man those first full-scale expeditions to neighbor
worlds. By the time he was out of college, with an engineering degree,
he might himself hope to be among those adventurers of space.

Burl was torn between two interests. Archaeology was both a profession
and a hobby in the Denning family. His grandfather had been among the
first to explore the jungle ruins of Indochina. His father, although a
businessman and industrial engineer, made annual vacation pilgrimages to
the ruins of the old Indian civilizations of the Americas. Burl had been
with him once before, when they had trekked through the chicle forests
of Guatemala in search of a lost Mayan city. And now they were again on
a quest, this time for the long-forgotten treasure of the Incas.

Burl was thoroughly familiar with the techniques of tracking down the
ancient records of mankind. He got along well with natives and
primitive people; he knew the arts of wilderness survival; he knew the
delicate techniques of sifting sand and dirt to turn up those priceless
bits of pottery and chipped stone that could supply pages of the
forgotten epics of human history.

However, later in the day it seemed as if their particular camp had
petered out. There were ruins there--a broken-down wall, a dry well and
a bit of eroded bas-relief lying on its side. Burl's father looked at
him thoughtfully. The tall, sandy-haired youth was sitting astraddle a
pile of dust, methodically sifting it through a wide-mesh strainer. A
large pile of sifted sand gave evidence of the length of his efforts,
and one broken bit of clay was the only result he had obtained.

Two of the Indian guides sat patiently in the shade, watching them. One
was digging slowly, turning up more dirt to be sifted.

"I think we've had enough here," said the elder Denning. "Burl, you can
knock off. Tomorrow we'll pull up stakes and see what is in the next
valley. We'll try to follow that old Inca road over the mountains. I
don't believe anyone has ever penetrated there--and the airplane surveys
indicated some evidence of human dwellings."

Burl nodded, and set the sifter down. He'd learned to curb his natural
energ