fice"
had a second canopy roof built above it and extending out on all sides
like a wooden umbrella. Thick pitch fried almost audibly from the fir
boards when the sun drove straight from overhead, but beneath their
shelter the heat was more bearable.

By an open window, where a hot breeze stirred sluggishly, Rawson sat
in silent contemplation of the camp. His face was as copper-colored as
an Apache's and as motionless. His eyes were fixed unwaveringly upon a
distant derrick and the blasted stub of a big drill that hung unmoving
above the concrete floor.

But the man's eyes did not consciously record the details of that
scene. He saw nothing of the derrick or of the heat waves that made
the steel seem writhingly alive; he was looking at something far more
distant, something many miles away, something vague and mysterious,
hidden miles beneath the surface of the earth.

"Heat," he said at last, as if talking in a dream. "Heat, terrific
temperatures--but I can't make it out; I can't see it!"

The younger, broad-shouldered man, whose khaki shirt, thrown open at
the neck showed a chest tanned to the black-brown of his face, stopped
his restless pacing back and forth in the hot room.

"Yes?" he asked with a touch of irritation in his tone. "There's
plenty of heat there--heat enough to melt off the shaft of that
high-temp alloy! What the devil's the use of wondering about the heat,
Dean? What gets me is this: the shaft has been plugged again. Now,
what kind of...."

* * * * *

Dean Rawson's face had not moved a muscle during the other's outburst.
His eyes were still fixed on that place that was so far away, yet
which he tried to bring close in his mind, close enough to see, to
comprehend the mystery that should be so plain.

"Lava wouldn't do it!" he said softly. "No melted stone would melt the
Krieger alloy, unless it was under pressure, which this was not.
There was no blast coming out of our shaft. Yet we dipped into that
gold; we stuck the drill right down into it. But what did we go into
the next time? What did we dip into?"

He swung quickly, violently, toward Smithy who was facing him from the
middle of the room. He aimed one finger at him as if it were a pistol,
and his words cracked out as sharply as if they came from a gun:

"That tube you sent down--that piece of casing! How was it burned?
Were there straggling ends, frozen gobs of metal? Did it look like an
old-fashioned