the
floor when we started, and didn't seem to experience much difficulty
when we stopped." He looked thoughtful for a moment. "You know, when
Torlos was bending that crowbar back there in the ship, I picked up a
curious thought--I wonder if--" He turned to the giant alien. "Torlos,
you once gave me the thought-idea 'bone metal'; what is that?"

Torlos looked at him in surprise and then pointed mutely to a heavy belt
he wore--made of closely woven links of iron wire!

"I was right, Morey!" Arcot exclaimed. "These men have _iron bones_! No
wonder he could bend that crowbar! It would be as easy as it would for
you or me to snap a human arm bone!"

"But, wait a minute!" Morey objected. "How could iron grow?"

"How can stone grow?" countered Arcot. "That's what your bones are,
essentially--calcium phosphate rock! It's just a matter of different
body chemistry. Their body fluids are probably alkaline, and iron won't
rust in an alkaline solution." Arcot was talking rapidly as they
followed the aliens down the long corridor.

"The thing that confirms my theory is that elevator. It's merely an
iron cage in a magnetic beam, and it's pulled up with a terrific
acceleration. With iron bones, these men would be similarly influenced,
and they wouldn't notice the acceleration so much."

Morey grinned. "I'll be willing to bet they don't use cells in their
prisons, here! Just magnetize the floor, and the poor guy could never
get away!"

Arcot nodded. "Of course, the bones must be pure iron; their bones
evidently don't retain any of the magnetism when they leave the field."

"We seem to be here," Morey interrupted. "Let's continue the discussion
later."

Their party had stopped just outside a large, elaborately carved door,
the first sign of ornamentation the Earthmen had seen. There were four
guards armed with pistols, which, they discovered later, were powered by
compressed air under terrific pressure. They hurled a small metal slug
through a rifled barrel, and were effective over a distance of about a
mile, although they could only fire four times without reloading.

Torlos spoke briefly with the guard, who saluted and opened the door.
The two Earthmen followed Torlos into a large room.

Before them was a large, crescent-shaped table, around which were seated
several men. At the center of the crescent curve sat a man in a gray
uniform, but he was so bedecked with insignia, medals, ribbons, and
decorations that his uniform