“Here, for instance, is this man Remedios.  Evidently he was in league with the Mexican bandits who attacked us, and it was his part of the conspiracy to stage a breakdown so that we could be easily attacked.  Now who were the bandits, and what did they want?  Were they ordinary robbers after money, or was their object something deeper?  Was it part of this plot against our oil interests?”

He paused to puff his cigar into renewed life.  All three chums had been listening with eager attention.  Now Jack Hampton spoke.  Mr. Temple earlier had elaborated for Jack’s benefit his theory that a faction of Mexican rebels was responsible for the outrages of which they had been the victims, hoping thereby to embroil Mexico and the United States and thus cause trouble for President Obregon.

“Mr. Temple,” said Jack, leaning forward, “I do not believe those bandits were after money.  Didn’t it strike you all as strange that they were in an auto?  Well, it did me.  The bandits of the border usually are mounted on horseback.  These men, on the contrary, had a high-powered car.  No, that attack was due to a carefully laid plan.  And do you know what I think their purpose was?  It was to capture you.”

Bob and Frank, elbows planted on the table, leaned forward surprised.  Mr. Temple, however, showed no surprise, but merely looked thoughtful.

“You see,” continued Jack, “you are an American of wealth and position.  They already have captured father.  Now, if they were to capture you, there certainly would be some commotion at Washington, the national capital, that would make trouble for President Obregon of Mexico.  Maybe another punitive expedition would be sent into Mexico, like General Pershing led in the time of Carranza, after Villa’s raid on Columbus, New Mexico.  At least, that’s what they expect, I guess.”

Mr. Temple nodded, but remained silent.

“But, Jack,” demanded Frank, “if you are right in your surmise, then it means that these fellows knew in advance of our coming.”

“Yes,” said Jack, “that’s the puzzling thing about it.”

“Anybody here know we were coming?” asked Bob, speaking for the first time.

“Sure,” said Jack, “Gabby Pete knew.  And Rollins, father’s assistant.  But you met the one, and you know he can be trusted.  As for Rollins, I don’t know much about him.  He’s a queer, silent man.  Not here tonight, because he left early this morning to see a man on business over here some twenty miles or so.  He said he might not return tonight.  But I know father trusted him.”

“Then, Jack, there is one other thing to be considered,” said Bob.  “And that is, has anybody among our enemies—­for I suppose we can call them that—­listened-in when we spoke by radio?”

“Of course,” said Jack, “with all these amateur receiving sets in use nowadays it is pretty hard to get absolute secrecy.  But, in the first place, since that Washington conference, the government has limited the use of certain wave lengths.  Now we are licensed to use an 1,800 metre wave length, and I imagine there are very few—­at least in this region—­who could ‘tap’ our conversation.  In addition, of course, we used our code in discussing when you would arrive.”