Whether the men heard what he said or not, they turned and shook their fists in the direction of the scouts; and from the threatening gestures that followed this action it was plainly to be seen that they did not mean this to be the last time they expected to meet the little party.
Rob turned to Lopez when the pair had vanished from view, and he could no longer catch the heavy thud of their horses' hoofs on the hard ground.
He found the guide frowning, and this fact told Rob what to expect.
"That spells trouble for us, doesn't it, Lopez?" he asked; while Tubby, Merritt and Andy hung upon what was passing between guide and patrol leader.
The Mexican shrugged his shoulders.
"If they can make it so, we will be followed, young señor," he remarked. "You saw for yourself they were Federal cavalrymen, the same that General Salazar he have send out to cut the railroad between Chihuahua and the river. All men who fight for Huerta hate Yankee gringoes; and they see these uniforms, so they understand you are Americano soldiers. That is bad!"
"So that's the way the land lies!" remarked Merritt. "Well, we do not intend taking off these good old suits and wearing anything else, not if we know it. But see here, Lopez, what if those fellows should take a notion to sneak around on us, and try a shot from the rear?"
"Not much chance of that, with all these thickets around, which Lopez calls the chaparral," Rob told him; "but I'll just wander off a bit, and see if I can glimpse them going. If that fails, I'll keep watch while the rest of you eat breakfast. Get busy, Andy and Tubby, so we'll have that agony over in a hurry."
"Agony!" repeated Tubby indignantly. "Well, I like that, now, don't you, Andy? As if eating could ever be a task!"
Passing out of the hidden camp, Rob found a place where he could get an uninterrupted view of the lower country. And it was not long before he discovered two mounted men, whom he easily recognized as their unbidden visitors, spurring away as fast as their horses could take them. When the scout saw them look back several times, he no longer doubted that they were positively the men he had come to watch.