"He has some good reason for refusing to accommodate us, I'm afraid," Bob said just then, as if he too had read the signs of that set countenance.
"Why don't you answer me, Moqui?" Frank insisted, bent on knowing the worst. "We are on the way now to find the man who gave you this letter that talks. We have some good news for him. And you can help us if you will only tell in what part of the Grand Canyon Echo Cave lies."
The Indian seemed to ponder. Evidently his mind worked slowly, when it tried to grapple with secrets. But one thing he knew, and this must be some solemn promise he had made the man of science, never under any conditions to betray his hiding-place to a living soul.
"No can say; in canyon where picture rocks lie; that all," he finally declared, and Frank knew Indians well enough to feel sure that no torture could be painful enough to induce Havasupai to betray one he believed his friend, and whose magic talking paper he carried inside his shirt, to prove his good character.
"That settles it, Bob, I'm afraid," he remarked to his chum, who had been listening eagerly to all that was being said. "You might try all sorts of terrible things and he wouldn't whisper a word, even if he believed all we told him."
"That's tough," observed Bob; "but anyhow, we've got something out of it all, because we know now that the silly old professor must be hiding in one of those cliff caves, trying to read up the whole life history of the queer people who dug their homes out of the solid rock, tier after tier, away up the face of the cliffs."
"True for you, Bob, and I'm glad to see how you take it. I had hoped the Moqui might make our job easier, as he could do, all right, if only he wanted to tell us a few things. But we're no worse off than we were before, in all things, and some better in a few."
"I wish I could talk Moqui," declared Bob; "and perhaps then I'd be able to make the old fellow understand. Perhaps, Frank, if you gave him a little note to Uncle Felix, he might promise to take it to him later on!"
"Hello! that's a good idea, I declare," exclaimed Frank; "and I'll just do that same while I think of it."
He immediately drew out a pad of paper, and a fountain pen which he often carried for business purposes, since there were times when he had to sign documents as a witness for his father.