"It's Morales. He and the German must have overcome your friend in some way. And I think he's got the Calomares ranch on the phone and is giving warning that your friends are on the way."
Frank groaned.
"Then when Jack and Bob land, they'll be surprised and captured. Oh, can't we do something?" Excitedly he jumped to his feet. "Let's put the radio out of commission."
Stone also leaped up and laid a restraining hand on his arm.
"No, no. Wait a minute. The damage is done already. These fellows already have given sufficient warning to put them on guard at the ranch, even though they can't have told the whole story."
They stood undecided, looking at each other, in the starlit darkness. With an exclamation, Frank seized Stone by the arm. In his excitement, he shook it.
"Jack and Bob both clamped the headpieces on when they left in the airplane," he said. "And Jack tuned the radio to the pitch of this station, in order to be able to call us after rescuing his father. Why, he must have heard Morales give his warning! Yes, sirree. Why this isn't so bad!"
In their relief, the two laughed a trifle hysterically. In a moment, however, Frank sobered again.
"Just the same," he said, "the ranch would get the warning, unless—"
"Unless what?"