"I think they must be, Bob, because all the tracks point one way, showing that the three men never came back. If they left the cave it must have been by some other way."
"No use asking why they would want to get in touch with Uncle Felix!" continued Bob, as if bent on finding out everything he could in connection with the case.
"We know what their reason was," Frank made answer. "When Abajo, hanging about the window of our ranch house, heard what we had to say about the message that came floating down the Colorado in that bottle, and carried the wonderful news to his employer, Eugene Warringford, he set the game going that must end right here. He has come with the intention of making Professor Oswald turn over that option to him; and he'll do it unless something we can offer prevents."
"But Frank, if the Moqui carried that note of yours to Uncle Felix, he would be on his guard, and absolutely refuse to sign away the papers?"
"I hope he will, but I fear that those three scamps are up there right now, trying to coax or bulldoze him into signing," Frank said, with a tightening of his lips, and a flash of his clear eyes.
"Then we go up, and put a spoke in their wheel, do we?" asked Bob, looking as if he were ready to make the start instantly, if his comrade but gave the word.
Frank glanced around him a little uncertainly.
"I've got a good notion to try it," he muttered as if talking to himself.
"What's that you say, Frank?" asked his companion, who had caught the words, and did not know what to make of them.
"I didn't tell you, Bob," Frank remarked; "but during the night I thought I heard a voice calling far away yonder. And somehow it struck me at the time that there was a familiar cowboy yell about it."