All at once Andy uttered an exclamation. There was such a note of alarm in his voice that Merritt looked up from his paper, and Tubby whirled around so as to face the other.

"What ails you now, Andy?" demanded Merritt.

"It's Rob!" exclaimed the scout addressed. "I just saw several soldiers creeping along the trail he must use coming back; and they mean to lie in ambush for him!"

CHAPTER XX.

"TRUST ROB!"

When Andy said that, both Tubby and Merritt felt a cold chill pa.s.s over them. It could be easily understood that if those vindictive Regulars had a chance to fire on the unknown party who wore the khaki of the United States soldiers, and who, they must know, had been sending messages from the rock jutting out above, there was no reason to believe that they would have the least pity because he turned out to be a boy.

There were many mere lads bearing arms among the followers of Villa and of President Huerta--there always are when revolution stalks through a land and war clouds are in the air--so that the taking of a boy's life did not mean anything unusual to these grim fighters.

But Merritt was alive to the importance of letting Rob know of the peril that was lying in wait for him on the back trail. If he slipped away and started to come down the side of the rugged slope, there was always a terrible chance that he might know nothing of the three Mexican Regulars lying under the rocks like genuine bushwhackers, ready to pour a deadly volley in his direction as soon as they felt that he was in their grip.

"Quick, Tubby, try and attract his attention again--tell him for goodness' sake to wait up there and take another message!"

Merritt almost shrieked this as he sprang toward the fat chum. Tubby instantly started the human windmill in motion again, waving his flag at a great rate, and forming the signal "1111--3: Wait a moment," that would tell the boy on the crag there was still something of vast importance to be wigwagged to him.

"I can see him there yet!" said Andy, though his voice trembled as if he were quaking with suspense.

"Yes, but his back is this way!" groaned Tubby, still keeping busy with his flags.

Merritt even put his hands to his mouth and shouted the name of the patrol leader several times, as though hoping with this primitive megaphone to be able to attract the attention of the other; but apparently sounds did not travel upward as well as they do on the level ground. At any rate, they could not see Rob give the first sign of turning; and he seemed to be busy watching something beyond, perhaps the soldiers who were crawling through that little ravine under the railroad track, a mile or more away.

"What if he starts down without once looking this way?" asked Andy.

"Oh! Ginger snaps and pop-guns! Don't mention it!" groaned Tubby.

"But that wouldn't be like Rob!" a.s.serted Merritt, just as though he might be trying the best way he knew to bolster up his own courage with this hope. "It would be more his style to take a last look this way to see if we had scattered to carry out his orders. Keep doing it right along, Tubby, while we all watch and hope he'll turn around soon!"

It was an anxious time for those three lads, and one they were not likely to forget soon, either.

All at once a whoop went up from Tubby.

"He's turned around, and is looking this way!" he exclaimed.

"Keep going, then; faster, Tubby!" cried Merritt. "Tell him to wait up--very important!"

"There he is, starting in to wave!" cried Andy.

"W-h-a-t d-o y-o-u w-a-n-t?" came the question from above, with every one of the three eager scouts below spelling it aloud.

"Stay where you are--great danger--three Federals in hiding on trail you took going up. If you must come down, pick another route!"

Tubby sent all of this, Merritt supplying him with the words in rotation; and evidently it was read correctly, for immediately after the message ceased, Rob sent back his "O. K.," and added: "Don't fear for me; I can take care of myself. So long!"

"He's gone!" cried Tubby, as the last fluttering letter came from above.

"Yes, and slipped out of sight just as if he meant to come back the same way he took going!" interjected Andy in dismay.

"That's all right," added Merritt. "Don't you see it must have been just a clever little stunt of Rob's, meant to fool the three cavalrymen who are lying in wait down on that depressed route he took going up? He reckons that they've been watching him all this while. So he just made out to have no suspicion that he knew about their game. Trust our Rob for keeping his wits about him! He'll slip around somehow, and leave them in the lurch."

"Say, I hope now none of that outfit can read wigwag work!" Tubby remarked, with a new line of trouble appearing on his usually smooth forehead. "Because then they'd know what I told Rob, and of course they'd change their position so as to cover the ground all along."

"Not one chance in a thousand that a single Federal ever took a lesson in signal work with the flags," Merritt told him. But evidently he was not so wholly free from fears himself, for immediately afterward he went on to say: "Perhaps I'd better be hunting Lopez up and telling him all that's happened. Out of grat.i.tude for what Rob has done to save them from being taken by surprise, these rebels may consent to make a little sortie and chase the three fellows up there away."

"A splendid idea, Merritt!" declared Andy, while Tubby burst out:

"Gee! but wouldn't it be just glorious to turn the tables on that lot and send them flying over the hill? Hurry up, and see if you can't get our rebel friends to make a start. They could charge right up that hill and scare the ambushers off like hot cakes. Go along, Merritt, and don't let the gra.s.s grow under your feet!"

Merritt was off even while Tubby spoke. He was something like Rob, for whenever he had an idea he believed in carrying it out with speed. In this case it was essential that no time should be lost, for at any minute one of the armed men who lay there in wait for Rob might find an opportunity to get a shot at him, with a result that neither Tubby nor Andy dared allow themselves to consider.

Both of them continued to stand there, keeping their eyes glued on the side of the rise, at about the spot where they knew the soldiers lay hidden. More than a few times one or the other believed he could detect some slight movement, as though the men might be taking an observation; but the distance was so great they could not be sure, and no doubt their fears magnified many things.

"He's found Lopez, and is talking to him right now!" Andy said, referring to Merritt, after a little time had elapsed.

"Yes, and you can see that our guide believes the news mighty important, because already he's beckoning to that captain who's carrying a sword, even if he hasn't any uniform," Tubby continued. "I hope now the feller isn't going to show the white feather and just shrug his shoulders the way they're so fond of doing down here, as much as to say Rob'll have to take care of himself. That would be a burning shame, wouldn't it, Andy?"

"But I don't believe they'll act that way," the other told him consolingly. "I reckon these rebels are fighters, and they'll think it a bully good chance to get one back on the enemy by knocking over three of the Regulars. See, he's showing a whole lot of interest right now.

There, Merritt is pointing up at the place where we know the ambushers are squatting. Will they sally out and chase them away? Oh! I hope so, I hope they will!"

"It looks as though they might be thinking of doing that very thing, doesn't it, Tubby?" Andy again burst out, a ring of satisfaction in his boyish voice. "See, that captain is yelling something to his men, for a lot of them are running up, waving their guns, and chattering all sorts of things--like a pack of monkeys finding a cocoanut. Make your mind easy, Tubby; there's going to be something doing soon!"

All Tubby made answer was expressed in one word:

"Bully!"

Evidently Merritt had managed to tell Lopez what a great service Rob had done in making his way to the top of the elevation, and sending word as to what the enemy was doing; and the guide had in turn transmitted this to the rebel chief, upon whom it must have made considerable impression, for he was plainly excited and bent upon discharging his obligations toward the signal sender, according to the plan suggested by the Eagle's corporal.

A dozen men were told off and given hurried instructions. They immediately ran the length of the train, and then with loud shouts and waving guns started for the foot of the rise, not bothering to take the trouble Rob had done to keep their movements secret. In fact, they must have meant to let the three Regulars know of their intentions as they scattered and started to climb the hill.

"There! Listen to that, will you?" shrilled the excited Tubby.

"It was a gunshot, sure as anything!" added Andy, hardly less stirred himself. "And I saw the puff of smoke up yonder where the three Regulars are hiding! Guess they know the game is up and mean to have a few cracks at the climbing rebels before they skip out!"

"And there goes a shot from below," said Tubby, "showing that our friends don't mean that the fun shall all be on one side. Yes, and listen to how the dogs of war keep on barking, will you, Andy? Whee!

isn't this exciting, though? I can just imagine how the bullets sing as they fly past! Hear 'em slash against the rocks! That will make 'em flatten out like pancakes!"

"All the while the rebels are climbing right along and getting nearer and nearer," Andy remarked, though not once could he tear his eyes away from the scene upon the side of the elevation. "They may hang on there too long, and find it a hard job to make their get-away, after all."

"I hope Rob isn't in line with all this shooting, or that he happens to run across the Regulars when they're making off!" Tubby pursued, voicing his fears.

"Trust Rob, Tubby; give him credit for horse sense, won't you?" scoffed the other scout. "And let me tell you, Tubby, that, if they do run across him, chances are they'll be sorry! Remember, Rob's got a gun along with him, and you've seen yourself how he could shoot at flying game many's the time. If he has to defend himself, he'll wing that lot in one, two, three order, give you my word for it!"

"I know that, Andy, as well as you do," agreed the fat boy; "and I guess I'm only saying what I do because my nerves are all unstrung. It's just awful to have to stand here watching, not able to lift a finger to help our chum! If I could only be in the thick of the thing, I wouldn't be croaking like this."