GAINING AN ALLY
Before mounting guard, however, Tom thought of their horses, a detail which the boys had forgotten in the quick march of events. He and Bob descended the slope, brought the animals into the valley where there was grass along the bed of a little stream trickling from a spring, and a few trees that provided shade. The horses were hobbled to prevent wandering too far, and then left to do as they pleased. They pleased, every one, to lie down at once and roll.
Upon their return to the cave, after Bob first had inspected the airplane and found it in tiptop condition and stocked with gas and oil, Tom mounted guard while the boys carried out their intention of taking Stone into the inner room for a conference.
Stone made matters easy for all concerned by speaking first, as soon as they all were out of earshot of Morales and Von Arnheim, and telling the boys he had guessed their identities.
"Of course, I don't know your names," he said, "but I reckon one of you is the son of that American bigbug old Calomares is holding prisoner up at his ranch. And the rest of you are his pals."
Bob's face fell. He had believed their identities were unsuspected. If this man could draw so clever a deduction, then their two other prisoners could do likewise. Moreover, if they carried out their original plan and went to rebel headquarters to enlist, would they not there, too, be suspected?
"Do the others guess who we are?" he asked.
"Don't know," said Stone. "I haven't been given much chance to talk to 'em, have I? But that German is smart, and he may suspect. But"—and with this statement he set at rest a part of Bob's fears—"my bed is pretty close to this room an' I have pretty good ears. I overheard some things that Morales and Von Arnheim couldn't hear, especially when you used the radio to call your father. Anyhow, I thought it was your father. Mostly you spoke in code, but I heard you call him 'Dad' a couple of times."
The three chums looked at each other, nonplussed. Stone laughed.
"Until I made out who you were," he said, "I thought you were some wild-eyed kids looking for adventure an' comin' to the right place to find it. But once I got a suspicion, it was easy to figure out the rest. You see, I knew about your owning the airplane that Von Arnheim stole, an' about your radio stations. When you started the generator that showed me you knew something about radio, an' that was another clue.