The Little Pets of Arkkhan

Lovable little balls of fur, incongruous on this bleak asteroid, forlorn and lonely ... who could be blamed for picking one up to take along—or for what happened thereafter?
At first, it was only a spider thread of sound. It was so soft, so caressing that it was like some healing unguent to the throbbing, burning boil that was Kent Knight's brain.
Tender and soothing as a wind-wafted melody in the first hush of evening, his grateful mind whispered. Then his mind was screaming as the spider thread grew jagged edges that clawed open the first pain wounds and tore them wider.
Knight lay on the hot rocky plain of the asteroid, sprawling convulsively where he was thrown when the first sharp hurt slashed at his mind.
And it was such a lovely little beastie. All furry and round and soft. What awful power did it hold? I just touched it. Like an Earthly kitten, a little furry butterball. I should have known better, but it was like being on Earth again.
That faint wondering thought whispered through the pain. But it was flung from him as his pain-frantic brain raged at his nerves, knotted and twisted his muscles.
There was too much agony for his mind to absorb. Knight sensed the waning of his mind's last resources with relief. The mental shocks ceased, his nerves and muscles quieted, and he drifted into a gentle darkness where there was no pain....
... It's gone , his mind observed gleefully. The thankful knowledge that wakefulness did not bring renewed pain smothered the other thing . But only for a moment.
Kent Knight. I am Kent Knight, I must remember that. I mustn't forget it. I mustn't let It make me forget. I am a man. My shipmates and I crashed on this asteroid in the Star Climber.
The other thing laughed at him— in him. The wee bit of Kent Knight which the other thing couldn't take or didn't want urged him to his feet. It didn't seem to mind his doing that much.
Knight drew his lean, rawboned frame erect. His muscles didn't hurt any more, he realized. He ran his strong fingers—which were shaking now—through his brown hair, ruffling the rock dust out of it. He looked toward the green oasis on the far side of the rocky plain where his friends were.