ling blast of force tore into the body of the
charging asteroid-cat, and the beast fell heavily a few yards away.

But as it fell, the small gray mass upon its neck suddenly detached
itself from the dead animal and scuttled swiftly forward. It moved
with blurring speed toward Bray, the nearest to it of the group.

The little gray creature was no bigger than a man's clenched fists
together. It was a gray, wrinkled featureless thing, except for
pinpoint eyes and the tiny clawlike legs upon which it scurried. It
reached Bray and ran swiftly up his legs and back as he swore
startledly.

Kenniston, made reckless of danger by his horror, yelled and lunged
toward the pilot. Bray was swearing and trying to slap at the gray
thing running up his back. But the little creature had now reached his
neck. Clinging there, it swiftly dug two tiny, needle-like antennae
into the base of his neck.

"Hold him!" Kenniston shouted hoarsely. "The Vestan has got him!"

Bray had undergone a sudden metamorphosis as the gray creature dug its
antennae into his neck. His face stiffened, became masklike.

The pilot turned and began to run stiffly toward the jungle.
Kenniston's leap almost caught him, but Bray lashed out a fist that
sent Kenniston sprawling.

"Don't let him get away!" Kenniston yelled, scrambling up.

But the others were too stricken by amazement and horror to interfere
in time. Bray had already plunged into the jungle and was gone.

"My God, what happened?" Captain Walls exclaimed dazedly. "Bray went
clean crazy!"

His gun was pointing at Kenniston and Holk Or as though he held them
responsible for what had occurred.

"He didn't go crazy, but he's lost now," Kenniston said heavily. "That
little gray creature was one of the Vestans."

"But what did it _do_ to him? That thing wasn't big enough to harm
anybody."

"That's all you know about it," said Holk Or ominously. "Those little
Vestans are the most dangerous creatures in the System."

"The Vestans," Kenniston added dully, "are semi-intelligent
_parasites_. The live by attaching themselves to and taking control of
some other creature's body. They do it by jabbing in those tiny,
needle-like antennae to contact the victim's nervous system.
Thereafter, the Vestan controls the victim's body absolutely. When the
victim dies or is hurt, the Vestan simply detaches himself and fastens
upon a new victim."

* * * * *

Horror was on the white