At a depth
of six feet it was a knife-blade seam; at ten feet it was only a red
discoloration in the bottom of their shaft.

"That seems to be all of it," he said to the others. "We'll send men up
here next year to go deeper and farther along its course but I have an
idea we've just mined all of the only iron vein on Ragnarok. It will be
enough for our purpose."

They sewed the ore in strong rawhide sacks and then prospected, without
success, until it was time for the last unicorn band to pass by on its
way south. They trapped ten unicorns and hobbled their legs, with other
ropes reaching from horn to hind leg on each side to prevent them from
swinging back their heads or even lifting them high.

They had expected the capture and hobbling of the unicorns to be a
difficult and dangerous job and it was. But when they were finished the
unicorns were helpless. They could move awkwardly about to graze but
they could not charge. They could only stand with lowered heads and fume
and rumble.

The ore sacks were tied on one frosty morning and the men mounted. The
horn-leg ropes were loosened so the unicorns could travel, and the
unicorns went into a frenzy of bucking and rearing, squealing with rage
as they tried to impale their riders.

The short spears, stabbing at the sensitive spot behind the jawbones of
the unicorns, thwarted the backward flung heads and the unicorns were
slowly forced into submission. The last one conceded temporary defeat
and the long journey to the south started, the unicorns going in the run
that they could maintain hour after hour.

Each day they pushed the unicorns until they were too weary to fight at
night. Each morning, rested, the unicorns resumed the battle. It became
an expected routine for both unicorns and men.

The unicorns were released when the ore was unloaded at the foot of the
hill before the caves and Schroeder went to the new waterwheel, where
the new generator was already in place. There George Craig told him of
the unexpected obstacle that had appeared.

"We're stuck," George said. "The aluminum ore isn't what we thought it
would be. It's scarce and very low grade, of such a complex nature that
we can't refine it to the oxide with what we have to work with on
Ragnarok."

"Have you produced any aluminum oxide at all?" Schroeder asked.

"A little. We might have enough for the wire in a hundred years if we
kept at it hard enough."

"What else do you need--was there enough