Mr. Temple paused for breath, and Frank, who had been computing mentally, interrupted.

“Our plane could do it all right,” he said.  “That is, if—­When did this happen?”

“Monday noon or a little later,” said Mr. Temple.

“Well, they stole it sometime Saturday night,” said Frank.  “Yes, they wouldn’t have had to make more than eighty miles an hour steady flying to do it.  But where did they get the petrol?”

“Why,” Bob reminded him, “we had her stocked with oil and gas.  And the spare tanks filled, too.  That wasn’t impossible.”

Mr. Temple resumed: 

“Haven’t answered your radiophone calls because didn’t get them.  Have been so busy running around in circles, haven’t had time to watch the telephone.  But if you call me when you get this shall be on the watch.  Father was kidnapped Monday noon.  No word from him.  Need your help.”

“He certainly does,” said Mr. Temple, emphatically, as he concluded reading.  “And he’ll get it, too.  Come on, boys, let’s call him up.”

Evidently Jack was on the watch for their signal, for he answered at once, and as soon as each had tuned to their private 1,800-metre wave length, the Temples and Frank were given the full details as to the kidnapping of Mr. Hampton.

He had been riding horseback across the range, miles from any oil derricks or pumping stations, on his way to visit one of the “independent” oil operators.

A lonesome cowboy hunting a stray was the only other human being in sight, and he was a half mile away.  Suddenly out of the sky swooped an all-metal airplane, glistening in the sun.  It made a beautiful landing on the sandy soil, bumped along over a few clumps of mesquite, and came to rest close beside Mr. Hampton.  The latter jumped from his horse, and started running toward it.  Evidently, Jack thought, his father believed the Temples and Frank had unexpectedly arrived.

Then the watching cowboy saw two men leap from the airplane and start for Mr. Hampton, who turned as if to run.  Thereupon, one of the two pointed a revolver at him and he turned, perforce, and surrendered.  He was put into the airplane, the two men again climbed aboard, and the machine soared up into the sky before the astonished cowboy could more than set his horse in motion.

All this Jack explained and then asked: 

“Mr. Temple, what would you advise me to do?”

“Does anybody else know of this?”

“Only the cowboy who saw it and I,” said Jack.  “This cowboy knew father by sight, and came direct to me with the information.  I’ve made him promise not to tell anybody until he hears from me.”

“That’s right, Jack,” said Mr. Temple, very earnestly.  “This information must not get out.  I believe, Jack, your father will be safe from harm and that the men who seized him are intent on embroiling Mexico and the United States.  Now we don’t want any more wars, Jack, and we must try to get your father back without the aid of troops.”