et," he
said. "It's our one weakness--the one Achilles heel in a m-machine that
was meant to be invulnerable."

He struggled to a sitting position. "You see, we were m-made as
s-soldiers and had to have a certain loyalty to the country that m-made
us. Only living things are loyal--machines are not. We had to think like
human beings."

Jordan's brows contracted as he tried to understand the robot.

"You mean you have a transplanted human brain?" he asked incredulously.

"In a way," Hall said. "Our b-brains are permallium strips on which the
mind of some human donor was m-magnetically imprinted. My mind was
copied f-from a man who stuttered and who got panicky when the going got
rough, and who couldn't kill a child no matter what was at s-stake."

Jordan felt physically ill. Hall was human and he was immortal. And
according to galactic decree, he, like his fellows, was to be manacled
in permallium and fixed in a great block of cement, and that block was
to be dropped into the deep silent depths of the Grismet ocean, to be
slowly covered by the blue sediment that gradually filters down through
the miles of ocean water to stay immobile and blind for countless
millions of years.

Jordan arose to his feet. He could think of nothing further to say.

He stopped, however, with the door half open, and asked: "One more
question--what did you want with the electrical generator plants on
Earth?"

[Illustration]

Slowly and without emotion Hall told him, and when he understood, he
became even sicker.

* * * * *

He went across to his cabin and stood for a while looking out the
window. Then he lit a cigarette and lay down on his bunk thinking. After
a time, he put out the cigarette and walked into the hall where he paced
up and down.

As he passed the cell door for about the tenth time, he suddenly swung
around and lifted the latch and entered. He went over to the robot, and
with a key that he took from his pocket, he unlocked the greaves and
chains.

"There's no point in keeping you bound up like this," he said. "I don't
think you're very dangerous." He put the key back in his pocket.

"I suppose you know that this ship runs on an atomic pile," he said in a
conversational tone of voice. "The cables are just under the floor in
the control room and they can be reached through a little trap door."

Jordan looked directly into Hall's face. The robot was listening with
great intentness.