art guys of Earth and Mars.
Brains--book-learning! Luke snorted.

Fuller was looking at him with calmly appraising gaze. Luke scowled
darkly, but the keen eyes that measured him did not waver.

"You're a fool, Fenton," came from the thin lips.

"What!" Luke advanced threateningly.

"I repeat: you are a fool." Still the gray eyes were unwavering.

"Why, you--you----" Spasmodically Luke's fingers closed down on the
spare shoulder with crushing force.

* * * * *

By not so much as the flicker of an eyelash did Fuller betray the pain
that must have come with that grip. He did not even wince, but swiftly
lashed out with a bony fist, raking Luke's cheek with sharp knuckles.
The blow stung, but was utterly futile. With a single cuff Luke could
send the man sprawling; with a single wrench of his powerful hands, snap
his spine. Yet he did neither, and the impulse to laugh coarsely died in
his throat. Here was courage of a kind he never had encountered; here a
man in whose bright eyes fearlessness and defiance mingled with a cool
disdain that brought the first real feeling of inferiority Luke ever had
experienced.

He relaxed his grip of Fuller's shoulder and his big hands fell loosely
at his sides. It was that action which saved Fenton. He did not know it
at the time, nor would he have believed it. But he was to remember many
times and finally to realize it, though he never fully understood.

"That's better," breathed Fuller. And the ghost of a smile crinkled the
corner of his mouth.

At the old man's warning Luke returned to his own work bench and was
industriously engaged when the guard's eye showed at the peephole. Then
the eye was gone and he grinned over at Fuller.

"How long you been in here?" he ventured.

"Five days in the sealed cell; ten altogether in the Workshop."

Luke pondered this. "How'd you get in the cell?"

"Same way you did--I struck a guard."

"No!" marveled Luke. "Mean to tell me you----"

"I had a reason to get in here," Fuller broke in mildly.

"You--you _wanted_ to get in?" Luke was incredulous.

"I did."

"My God, you ain't crazy, are you--wantin' to get yourself killed off
quicker?"

* * * * *

"No, that isn't it," Fuller explained patiently. "I've a plan to escape
and only by taking the chance of spending some time here could I obtain
access to the necessary materials. Fenton, I'm a scientist an