e void. He pressed softly upon the hand he held and pointed.

"See!" he said in a hushed tone. "There is something there!"

* * * * *

It took form slowly, a shapeless, round blur in the pale light. Inch by
inch it drifted toward them, until Chet moved one hand abruptly and
found he had created a ripple of light by which he could see more
clearly. And he saw before him a bulging, membraneous sac.

It had been smoothly spherical before; it heaved itself into strange
protuberances as he watched. He flipped his hand to set up another
vortex of light, and he saw the first rip that formed in the membrane.

Before his staring eyes the bag burst open; and Chet, who had wished for
some substantial thing, even a denizen of this wild world, found his
wish fulfilled. For the thin membrane tore in a score of places to
release a body from within--a shapeless, huddled mass of chalk-white
flesh in a wrapping of black leather that unfolded before his eyes and
became wings which waved feebly in their first attempt at flight.

The pallid body, supple as a giant worm, jerked spasmodically and turned
sightless eyes toward the watching Earth-folk. Then, as if drawn by some
magnet, invisible in the distance, the black wings began to beat the
air, and the creature moved off in a straight line toward some unknown
goal.

* * * * *

Another of the membraneous spheres drifted past in the light that came
from those fluttering wings. A second showed in repulsive shininess.
Chet was aware that there were many of the things about.

"Eggs!" he exclaimed with a disgust that partook of nausea, "And the
damnable thing hatched--right here!--before our eyes!"

And the girl gave the final explanation: "The Moon is just a great
shell. They lay their eggs, these half-human creatures that you saw, and
attach them to the inner surface of that shell. Then at a certain period
they come loose and float away. I never knew what became of them; now I
understand at last."

"You know all this!" protested Chet. "How can you know it? How long have
you been here?"

"I kept track of time for a while," said the voice beside him; "then I
forgot it when they took Frithjof away. But it must be about five years.
Five years of terror and vain hopes and wild plans for escape! And now
it ends--after five years!"

And Chet Bullard, within his metal helmet, was repeating in
bewilderment: "Five years! Haldgr