e unseen
being had first aroused in him. But it returned in a sickening wave
when he heard the short, shrill, coughing cries, hideously eager, that
greeted the opening of the door. And the quick rasping of naked claws
upon the floor. _Sounds from nothingness!_

He flung the powder at the sound.

A form of weird horror materialized before him, still half invisible,
half outlined with the white film of adhering powder: gigantic and
hideous claws, that seemed to reach out of empty air, the side of a
huge, scaly body, a yawning, dripping jaw. For a moment Thad could see
great, hooked fangs in that jaw. Then they vanished, as if an unseen
tongue had licked the powder from them, dissolving it in fluids which
made it invisible.

That unearthly, half-seen shape leaped at him.

He was carried backward into the room, hurled to the floor. Claws were
rasping upon the tough fabric of his suit. His arm was seized
crushingly in half-visible jaws.

* * * * *

Desperately he clung to the welding tool. The heated electrode was
driven toward his body. He fought to keep it away; he knew that it
would burn through even the insulated fabric of his suit.

A claw ripped savagely at his side. He heard the sharp, rending sound,
as the tough fabric of his suit was torn, and felt a thin pencil of
pain drawn along his body, where a claw cut his skin.

Suddenly the suit was full of the earthy fetor of the monster's body,
nauseatingly intense. Thad gasped, tried to hold his breath, and
thrust upward hard with the incandescent electrode. He felt warm blood
trickling from the wound.

A numbing blow struck his arm. The welding tool was carried from his
hand. Flung to the side of the room, it clattered to the floor; and
then a heavy weight came upon his chest, forcing the breath from his
lungs. The monster stood upon his body and clawed at him.

Thad squirmed furiously. He kicked out with his feet, encountering a
great, hard body. Futilely he beat and thrust with his arms against
the pillarlike limb.

His body was being mauled, bruised beneath the thick fabric. He heard
it tear again, along his right thigh. But he felt no pain, and thought
the claws had not reached the skin.

It was the yellow dog that gave him the chance to recover the weapon.
The animal had been running back and forth in the opposite end of the
room, fairly howling in excitement and terror. Now, with the mad
courage of desperation, it leap