Mexican answered. "He hire me with much money. He
buy thees machine inside, and we put him together. But he could no
make him work--it take too long. We watch, hear old man go down
to-night, and--"

* * * * *

The greaser stopped. "And so he sent you to get me, while he kidnapped
the old man and his daughter and forced them under the ground in their
own borer," Holmes supplied, and the other nodded.

"But I only mean to tie you!" he blurted, gesturing weakly. "I no mean
shoot! No, no--"

"All right--forget it," Phil interrupted. "And now tell me what Quade
expects to do down there."

"I not know, Senor," came the hesitant reply, "but...."

"But what?" the young man jerked.

Reluctantly the wounded Mexican continued. "Senor Quade--he--I think
he don' like thees old man. I think he leave heem an' the girl down
below. Then he come up an' say they keeled going down."

Phil nodded grimly. "I see," he said, voicing his thoughts. "Then he
would say that he and Professor Guinness are still partners--and the
radium ore will belong to him. Very nice. Very nice...."

He snapped back to action, and without another word hoisted the
Mexican onto his back and carried him into the shack. There he
cleansed the wound, rigged up a tight bandage for it, and tied the man
to one of the cots. He tied him in such a fashion that he could reach
some food and water he put by the cot.

"You leave me like thees?" the Mexican asked.

"Yes," Phil said, and started for the door.

"But what you going to do?"

Phil smiled grimly as he flung an answer back over his shoulder.

"Me?--I'm going to fix the wiring on those disintegrators in your
friend Quade's borer. Then I'm starting down after him." He stopped
and turned before he closed the door. "And if I don't get back--well,
it's just too bad for you!"

* * * * *

And so, a little later, once more the hushed desert night was cleft by
a furious bellow of sound. It came, this time, from a narrow canyon.
The steep sides threw the roar back and back again, and the echoes
swelled to an earth-shaking blast of sound. The oblong hut from which
it came rocked and almost fell; then, as the noise began to lessen,
teetered on its foundations and half-slipped into the ragged hole that
had been bored inside.

The descent was a nightmare that Holmes would never forget. Quade's
machine was much cruder and less efficient than the sphere