and the wave of flame wavered and sank into nothingness. While their
ear-drums continued the thunder, the three stared at the borer, not
daring to approach, yet striving to solve the mystery of why it had
sunk despite the up-thrust of ten rocket tubes.

As their eyes again became accustomed to the familiar phosphorescent
illumination, pallid and cold after the fierce orange flame, they saw
why--and their eyes went wide with surprise and horror.

A strange mass was covering the top of the earth-borer--something that
looked like a heap of viscid, whitish jelly. It was sprawled
shapelessly over the round upper part of the metal sphere, a
half-transparent, loathsome stuff, several feet thick in places.

And Phil Holmes, striving to understand what it could be, saw an awful
thing. "It's moving!" he whispered, unconsciously drawing Sue closer.
"There's--there's life in it!"

Lazy quiverings were running through the mound of jelly, pulsings that
gave evidence of its low organism. They saw little ripples of even
beat run over it, and under them steady, sluggish convulsions that
told of life; that showed, perhaps, that the thing was hungry and
preparing to move its body in quest of food.

It was alive, unquestionably. The borer lay still, but this thing
moved internally, of itself. It was life in its lowest, most primate
form. The mass was mind, stomach, muscle and body all in one, stark
and raw before their startled eyes.

"Oh, God!" Phil whispered through the long pause. "It can't be
real!..."

"Protoplasm--a monster amoeba," David Guinness's curiously cracked
voice said. "Just as it exists on the surface, only microscopically.
Primate life...."

* * * * *

The lock of the earth-borer clicked. Phil gasped. "Quade is coming
out!" he said. A little cry of horror came from Sue. And the metal
door opened.

James Quade stepped through, automatic in hand. He was fresh from the
light inside, and he could not see well. He was quite unconscious of
what was oozing down on him from above, of the flabby heap that was
carefully stretching down for him. He peered into the gloom, looking
for the three he had deserted, and all the time an arm from the mass
above crept nearer. Sue Guinness's nerves suddenly gave, and she
shrieked; but Quade's ears were deaf from the borer's thunder, and he
did not hear her.

It was when he lifted one foot back into the sphere--probably to get
out the searchlight--t