e he had looped it over one shoulder,
but Harkness motioned him back. The pistol was in his hand, but after a
moment's hesitation he returned that to his belt. His voice was low and
tense.

"Listen," he said: "we're no match for them with our bows. They are
hidden; they could pick us off as we came. And I can't waste a single
detonite shell on them while they keep out of sight. We can't go back;
we must go ahead. We will all make a break for it and run as fast as we
can toward the big altar--the pyramid. From there we can stand them off
for a while. And we will go now and take them by surprise."

He seized Diane firmly by one arm and steadied her as they dashed down
the slope. Chet and the professor were close behind. Each spine must
have tingled in anticipation of a shower of arrows. Chet threw one hasty
look toward the rear; the air was clear; no slender shafts pursued them.
But from the cover of the jungle growth came a peculiar sound, almost
like a human in distress--a call like a moaning cry.

* * * * *

They slackened their breath-taking pace and approached the great pyramid
more slowly. As they drew near, the great steps took on their real size;
each block was taller even than Chet, and he had to reach above his head
to touch the edge of the stone.

They walked quickly about; found a place where the great blocks were
broken down, where the slope was littered with debris from the
disintegrating stone that had sifted down from above. They could climb
here; it was almost like a crudely formed set of more normally sized
steps. They made their way upward while Chet counted the courses of
stone. Six, then eight--ten--and here Harkness called a halt.

"This--will do," he gasped between labored breaths. "Safe enough here.
Chet, you and Kreiss--spread out--watch from all--sides."

The pilot was not as badly winded as Harkness who bad been helping
Diane. "Stay here," he told Harkness; "you too, Kreiss; make yourselves
comfortable. I will go on up to the top. The moon--or the Earth,
rather--will be up pretty soon; I can keep watch in all directions from
up there. We've got to get some sleep; can't let whoever it is that is
trailing us rob us of our rest or we'll soon be no good. I'll call you
after a while."

* * * * *

The great capstone projected beyond the blocks that supported it; that
much had been apparent from the ground. But Chet was amazed at t