He did not pause to consider that the party at the cave in all likelihood was little better prepared than he with information.  The mere idea of doing something, of taking some action that would break up this horrible spell of waiting, appealed to him in his excited state.

But after hearing from Frank an account not only of the fight the latter had had to recover the cave, after once having been dispossessed, but also of the attempt to warn the Calomares ranch ahead of the boys’ coming which Morales had made, he began to wish he never had called Frank.

“Think of it,” he said to Dave Morningstar, after explaining the situation.  “In all likelihood all that clash of conversation in the air put them on guard at the Calomares ranch.  They were led to suspect all was not well.  And then when the boys landed they were captured.  That can be the only reason for our failure to hear from Bob 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.