When Bob eagerly took his repeating rifle from the hands of the Chinaman he exhibited all the evidence of great satisfaction; for he heaved a sigh of relief, and fondled his weapon in a way that caused his comrade to smile.

"I feel better now," Bob confessed; "because, to tell the honest truth, when you broke the news so suddenly it nearly gave me heart failure, Frank, to think that if those rascals sprang out at us we would be next door to helpless. Now let 'em be careful how they play their little game. But what does it all mean, do you suppose, Frank?"

"I can only make a guess, and that may be wide of the truth," the other admitted. "By some accident they managed to get on the track of the Moqui. Though Havasupai thought himself smart, he was no match for such a cunning rascal as Spanish Joe, who is said to be the best trailer along the Arizona border. And they followed him right here."

"That was last evening, just when you and I stood there down by the river, looking through the gla.s.ses up at the windows of the rock houses above," remarked Bob.

"Yes. Perhaps they didn't go up right then." Frank went on. "I admit that I can't just make out how long ago these tracks were made. A better trailer might, you see, Bob. If Old Hank Coombs were only here now I'd be glad to turn the whole business over to him, and play second fiddle."

"But some time between dark and morning these three rascals went in here, and surprised the hermit of Echo Cave--is that it, Frank?"

"It covers the case all right," came the reply.

"Say, do you think they are up there yet?" asked the Kentucky lad, in an anxious tone.

"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."

"Old Hank Coombs, perhaps, Frank?" suggested the other lad, quickly.

"That was on my mind, Bob. You know history often repeats itself. Once before, just when we seemed to need Hank the worst way, he came riding along as if he had heard us call. And I was wondering whether he might not be somewhere around here right now."

"That would be just prime, if only we could get in touch with him," Bob declared. "And, as your father wouldn't send Hank alone, there'd be one more cowboy along. That would make a party of four. Why, those three rascals would just shrivel, and throw up the sponge, if they saw us break in on 'em. But Frank, how about making the old range call?"

"D'ye know, I was just thinking it might do to try it," remarked the other.

"Then start in and give the whoop," Bob observed. "No harm done anyhow; even if they hear it up there. And while you're doing all that, I'll just drop on one knee here, and cover the crack in the wall. Suppose one of the lot should try and come out while we were off our guard. I'll make him surrender quicker than he can say 'Jack Robinson'!"

Presently there sounded upon the morning air the clear "cooee" of the range, particularly well known to every cowboy who had worked at Circle Ranch. Frank and Bob listened eagerly to learn whether there would come any response. If not, then they must take up the task of climbing that singular crevice by themselves; and finding out how affairs stood above.

Their suspense was short-lived, for quickly there floated to their waiting ears a responsive call. Turning toward the quarter from whence it seemed to come they saw a hat waving.

"It's Old Hank, sure it is!" exclaimed Bob, with a thrill of delight; for the burden of going up against three desperate characters was more than boy nature could stand without more or less uneasiness.

"That's Chesty with him," announced Frank, as two figures were discovered coming toward them. "Why, if we'd made all the arrangements ourselves we couldn't have done better, Bob. Here comes our reinforcements just in the nick of time. And if Eugene and his backers are still up yonder in the cliff dwellers' homes, they have stayed a little while too long, that's all."

In another three minutes the boys were shaking hands with Old Hank and Chesty; the latter with a cheerful grin on his face, as though he considered it quite a joke to break in on Frank's game at the finishing point.

Of course they were ignorant as to how matters stood. And Frank took upon himself the task of explaining all that had happened.

"Ther up yonder yet, then," announced Hank, after he had carefully inspected the footprints, and noted that they all pointed one way; "that is to say, if they ain't got an airyplane along as would allow of them flying off. An' Frank, when ye sez the word we'uns are goin' t' walk up this rock ladder t' see what sorter place the ole perfessor keeps."

"Then I say it now," declared Frank, anxious to have the thing settled one way or the other without further delay.

"Foller arter me, all of ye!" called the old plainsman, as he plunged into the gap.

CHAPTER XX

ANOTHER SURPRISE

"One thing, we won't need torches this time, Hank!" remarked Bob as he prepared to follow after the leader.

"I reckons not, Bobby," chuckled the veteran cowman, who knew that something about the situation must have recalled their entering that cave that day where sly old Sallie and her half-grown whelps awaited their coming with bared teeth.

Just back of Hank came Chesty, who was a very ambitious young fellow, and always to be counted on with regard to obtaining his proper share in every little excitement that happened. Then Frank filed along; and at his heels Bob climbed; while Charley Moi brought up the rear, bent on seeing all that might come to pa.s.s.

The crevice immediately began to mount upward, just as Frank had antic.i.p.ated it would. There were times when the climbing was pretty steep, and Frank began to wonder what sort of agile man this old and stubborn Professor Oswald could be, to overcome such difficulties so often, while in the pursuit of his hobby.

Bob was soon panting, but no less bent on "keeping up with the procession," as he himself put it. They had been going back from the face of the cliff pretty much all the time, so that there was really no chance to take an observation, in order to tell just how far up they had come.

Frank felt sure, however, after this labor had kept up for quite a long time, that they must now be getting near the top of the break, or where the crooked crack in the face of the rock ended.

He tried to picture what they would find. If Eugene and his reckless backers had been in possession of the place for some hours now, they must have tried all sorts of expedients in order to compel the professor to reveal the secret hiding place of the valuable doc.u.ment, and make it over to them. Nor would such heartless men hesitate long about adopting torture in order to force a confession from the unwilling victim.

Then Frank wondered if the three rascals would attempt any tactics looking to holding the attacking force at bay. They were well armed, no doubt, and having such a rich treasure hanging in the scales, it might be expected that they would hate to let it slip from their covetous grasp without putting up some sort of fight.

But all that could be left to Old Hank. For many years he had been the leading figure in all the affairs that centered around Circle Ranch. Did the rustlers run off part of the herd, the veteran was put in charge of the pursuing force. Sometimes the sly marauders got off scot free; but more often they paid dearly for their audacity in picking out Colonel Haywood's ranch as the scene of their foray.

Frank really had no fears as to the result, now that Hank had arrived on the scene to direct operations. The three schemers might give them some trouble, but they could not carry the day.

"Please let a fellow rest up a little, Hank!" came from Bob, finally.

The old cow puncher understood that the pace had been too warm for the tenderfoot; and he considerately halted. Perhaps none of the climbers were averse to a breathing spell before the final round. It would put them in better condition for the wind-up, whatever that might prove to be.

"Frank," whispered Bob, as he pulled at the trouser leg of his chum so as to induce him to bend down closer.