ob and
Jack."

Dave attempted sympathetic protest, but Mr. Temple shook his head and
groaned.

"No, something has happened to them," he said. "Oh, I was a fool to
let them go. I'll never forgive myself. If only they were not injured.
If only they were merely made prisoner, I----"

"Hey," said Dave, "look at that signal bulb. Somebody's calling us."

"It's only Frank, calling back, I suppose," groaned Mr. Temple.

But Dave took up a headpiece and began adjusting the tuner knob. In a
moment he tapped Mr. Temple on the bowed shoulder.

"Listen here," he said, and clapped the headpiece over Mr. Temple's
ears.

Similar anxieties to those ruling at the Hampton radio station had
been in control at the cave during the evening hours.

Frank had been frightfully anxious as the hours wore on with no word
from the boys. The flight to the ranch was a short one of only fifty
miles. Surely, if they had been successful, Jack and Bob long ere this
would have called him by radio in accordance with their agreement.

The poor boy stamped up and down the cave in such a fret that Tom
Bodine and Roy Stone made repeated efforts to calm him, but without
success. They began seriously to fear the effect of this anxiety upon
his system, already fevered by the several hard fights through which
he had gone in the last thirty-six hours.

Mr. Temple's call had done nothing to assuage Frank's anxiety. If
anything it had increased it. As he put aside the headpiece, he looked
so woebegone that Tom Bodine went up to him and laid an arm over his
shoulder.

"Now, look here, kid," he began.

But before he could proceed, Frank's glance caught the light flashing
in the signal bulb, and he leaped to the headpiece and microphone with
a glad cry.

* * * * *

"Father, we are all right. Mr. Hampton is freed."

At the cave in the mountains of Old Mexico and at the Hampton ranch
across the border in American territory, these welcome words uttered
in Bob's well-known voice were received with delight. Across mountain
and desert sped the message by radio. Modern science making possible
the utilization of the forces of the air brought this quick relief to
an anxiety that otherwise would have continued for hours at the least,
until Bob and Jack could have flown back to the ranch.

But neither Mr. Temple nor Frank took that thought into consideration.
To them radio telephony was an accepted fact, part of their daily
eq