"To explain to you, I must speak to you about things about which you
already know partially," answered Qril. "Before you were born, the human
you call Goat was one of a group of humans who sought ways to make
humans independent of the spaceships which bring materials from Earth to
Mars and create small islands of terrestrial conditions in the midst of
the Martian environment. When they met the natural resistance of those
humans who gain material advantage through operation of the spaceships,
they came into the desert to be free to work.

"Seeking to get far from the men who resisted their work, this group of
humans went to that area which you know as the Icaria Desert. Some of us
who are children of the past live at that place sometimes, and these
humans sought our help, knowing that we possess many remnants of the
knowledge that our forefathers had.

"But we had difficulty helping them. They were attempting to follow two
courses simultaneously, and both of them were wrong."

"I know something of those two courses," said Maya. "Some of them were
trying to develop human extrasensory powers so that materials could be
teleported from Earth, and the others were trying to change the human
body physiologically so that humans could live under Martian conditions.
But you say they were both wrong?"

"In each way that they followed, they sought to make humans partly like
us, the children of the past," said Qril. "We have the power to
communicate with our minds over a distance, and some of us are able to
transport things with our minds over a distance. We do not need your
rich terrestrial air, because we take oxygen directly from the soil and
store it in our bodies for combustion purposes.

"But humans and the children of the past are different forms of life,
and they cannot be made so much alike. It is possible for humans to
develop mental powers similar to ours, but this course would leave them
dependent upon importing materials from Earth, even though this would be
by mind transmission instead of by spaceship. The other course they
followed could not succeed, because the human body cannot be altered so
that it is able to take oxygen from the soil and store it for later
use."

"But you're wrong!" exclaimed Maya. "Goat Hennessey had succeeded in
developing some humans who could live without oxygen in the air for a
time. His experiments were imperfect, it's true, but they were able to
do that."

"The imperfect humans t