"Steady on, boy, steady on," said Mr. Harkness in an even, cool tone.

"And we without a spavined cayuse to follow 'em!" raged one of the cow-punchers.

As he spoke, the three tormentors of the ranch party topped the little rise.

As they did so, Clark Jennings rose in his stirrups and faced back.

"Ye-ow!" he yelled defiantly, waving his hat mockingly toward them.

Bang!

The sombrero was suddenly whirled out of the youth's hand as if some invisible grasp had been laid upon it.

Blinky looked apologetically at Mr. Harkness, and then carefully blew the smoke from the barrel of his pistol, the weapon with which he had just punctured Clark's headgear.

"Awful sorry, boss," he said contritely, "but I just plumb couldn't help it."

"Well, I don't know that I blame you," said Mr. Harkness, as the Clark Jennings party vanished in a hurry.

The encounter with the three ne'er-do-wells had, however, changed the rancher's plans. Deducing from the fact that Hank Handcraft had Rob's hat in his possession, that the boy must have escaped from the Indians in some miraculous way, it was concluded that it would be a mere waste of effort to pursue the Moquis. The search must now be made for Rob himself. Even Tubby's spirits were dashed by the disturbing occurrences of the last few hours, and he and Merritt were both silent as the party made its way back to the cliff where the ponies had been left the day before. The plan now was to mount and scatter through the range.

"We'll run a fine-tooth comb through it," was the emphatic way Mr.

Harkness put it, "and if we don't find the boy, it'll be because he isn't on the top of the earth."

All that day they retraced their steps, and at night made camp not far from the entrance to the tunnel. They did not dare to proceed in the dark, for fear of once more losing their path, and even more valuable time. It was not a lively party that settled down in the evening glow for a hastily cooked and not over-abundant supper. Even Tubby seemed distracted and worried.

Suddenly Merritt, who was walking up and down, trying to evolve some theory to fit the facts in Rob's case, gave a shout and pointed over to the southwest.

"Look, look!" he shouted. "Off there--what is it?"

The boy's keen eyes had espied a thin spiral of blue smoke ascending from a hilltop against the burnished gold of the sunset.

"A signal fire!" announced Blinky, after an interval.

"It may be Rob signaling for help!" exclaimed Merritt, as the smoke rose and vanished and rose and vanished at regular intervals.

"No, it ain't him. The Boy Scouts use the Morse, don't they?"

"Yes. What has that to do with it?"

"Well, this is Injun code."

"Indian?"

"Sure. The Injuns have as distinct a smoke-signal code as we have a wireless system. It works just as good, too, from what I can hear. Now, if we had their code book we----"

"What, the Indians have a code book?"

"You bet."

"Where?"

"In their rascally heads, son, where it's safe," rejoined the cow-puncher.

"Hullo, look! There's an answer," cried Tubby, suddenly pointing to another hilltop some distance from the first.

Another thin column of smoke was rolling upward from it in evident answer to the first.

"Those fellows are making a date," decided the rough-and-ready Blinky.

"I'd like to be on hand when they keep it, and maybe we'd find out something about Rob."

CHAPTER XVII.

IN THE CLUTCHES OF THE GRIZZLY.

Blinky's conviction that the signaling had something to do with Rob would have been strengthened if he could have been so stationed as to watch the making of the first smoke telegraph Merritt noticed. On the distant hilltop Clark Jennings, Hank Handcraft and Bill Bender were stooped over a fire of green wood, alternately covering and uncovering it with a horse blanket. The signaling was being done under Clark's direction, as neither of the Easterners knew anything about the Indian smoke language. Clark, during his long residence in the West, had picked up his knowledge of it from Emilio Auguardo, the halfbreed who had once worked on his father's ranch. Through this man, too, he had become quite an intimate of the Moquis, as we have seen.

"Douse it! Uncover it. Douse. Uncover. Douse. Uncover."

Clark Jennings's commands came in regular rotation, with differing intervals between each order. In all essentials, those three enemies of the boys were using a telegraph code antedating by centuries the system in use to-day on our telegraph lines.

"Ought to be getting an answer soon," muttered Clark, shading his eyes with his hand and standing erect on an upraised slab of rock, the better to command a view of the distant hills in the section in which he had reason to believe the Moquis had proceeded.

"Hold on! Douse that fire!" he cried suddenly.

Against the sky, not more than five miles distant, an answering thread of smoke had unrolled, like the coils of a slow serpent. Up it wavered and then stopped abruptly, to be followed by another puff. It was as if a locomotive lay beyond the distant hill. The puffs of smoke resembled the vaporous belchings of an engine stack when it is starting up.

"They say for us to wait here and they will send a messenger," announced Clark finally.

"Well, I guess we can wait as well as anything else," rejoined Hank Handcraft, extending himself lazily on the sun-warmed ground. "Are they going to send a pony?"

"Don't know," rejoined Clark shortly. "Wonder what we'll do if Harkness. .h.i.ts our trail?"

"Don't bother about that. He'll be too busy rounding up that boy Rob,"

replied Bill Bender. "Queer where that kid went to."

"Queer is no word for it," agreed Clark; "and what bothers me is that we are likely to have trouble with him yet if we're not careful."

"You think he is alive, then?"

"Must be, unless he melted into thin air."

"That's so."