your
face-plate wide, and warn me at the slightest sound or sight of
possible danger."

The Negro nodded and moved as silently as was possible in his
space-suit to obey. And Carse turned again to the thing to which he
had made a promise.

* * * * *

The icy-glittering case was full of a colorless liquid in which were
grouped at the bottom, several delicate, colored instruments, all
interconnected by a maze of countless spidery silver wires. Sheathes
of other wires ran up from the lower devices to the case's main
content--five grayish, convoluted mounds that lay in shallow
pans--five brutally naked things that were the brains of scientists
once honored and eminent on Earth.

Their bodies has long since been cast aside as useless to the ends of
Ku Sui, but the priceless brains had been condemned to live on in an
unlit, unseeing deathless existence: machines serving the man who had
trapped them into life in death. Alive--and with stray memories, which
Ku Sui could not banish entirely, of Earth, of love, of the work and
the respect that had once been theirs. Alive--with an unnatural and
horrible life, without sensation, without hope. Alive--and made to aid
with their knowledge the man who had brought them into slavery
unspeakable....

Hawk Carse's eyes were frigid gray mists in a graven, expressionless
face as he turned to the left of the case and pulled over one of the
well-remembered knife switches. A low hum came; a ghost of rosy color
diffused through the liquid in the case. The color grew until the
whole was glowing jewel-like in the dim-lit laboratory, and the narrow
tubes leading into the undersides of the brains were plainly visible.
Something within the tubes pulsed at the rate of heart-beats. The
stuff of life.

When the color ceased to increase, Carse pulled the second switch, and
moved close to the grille inset in a small panel above the case.

Slowly, gently he said into the grille:

"Master Scientist Cram, Professors Estapp and Geinst, Doctors Swanson
and Norman--I wish to talk to you. I am Captain Carse, friend of
Master Scientist Eliot Leithgow. Some days ago you aided us in our
escape from here, and in return I made you a promise. Do you
remember?"

There was a pause, a silence so tense it was painful. And then
functioned the miracle of Ku Sui's devising. There came from the
grille a thin, metallic voice from the living dead.

"_I remember you, Captain Carse, a