“Watch the fire!” was all the answer he received; but it was enough.

Bob knew his chum was anticipating seeing a change take place at any minute now; that he fully believed the two agile cow punchers must have had ample time to crawl up the incline.

He found himself wondering whether the sentry would make any outcry. Of course any such sound would threaten the success of their plans, since it must excite the curiosity of the rustlers, and lead to an examination.

But then Scotty knew what he was about, and would hold his hand until he could be sure of silence and success. Somehow Bob found himself putting the utmost faith in the cowboy. The remarkable manner in which Scotty had led them thus far seemed to stamp him as capable.

The glow of the end of the cigarette could still be seen in the shadows under that clump of trees that clung to the face of the mountain. Of course the man who smoked had consumed more than one little paper-bound weed during this time, but Mexicans have a way of rolling them deftly between their fingers when smoking, and lighting one from the end of another, in succession.

Straining his eyes, Bob endeavored to make out some moving form near that point upon which the

attention of the watchers below was concentrated. In this he did not succeed. Those who were creeping upon the man who lolled there, enjoying his smoke, and perhaps dreaming of some day when he could return to his native country with his pockets filled with gold, were moving with all the care that marks the advance of the gray panther, when approaching his intended prey.

Bob was becoming uneasy. The strain began to tell upon him, wholly unaccustomed as he was to such scenes of excitement and suspense. He even found himself imagining all sorts of unpleasant accidents as happening to Scotty, anyone of which would interfere with the successful carrying out of his plans.

But Frank seemed to have no such fears. When Bob started to mention what was worrying him, his chum immediately eased his mind.

“Don’t you believe it for a minute, Bob,” he whispered. “Scotty is right close to that rustler now, and perhaps before you could wink fifty times he’ll make his move. Keep on watching the light. When it suddenly goes out, and doesn’t die down, you’ll know something has happened!”