Nor were the men of Villa slow to return the fire, since they seemed to have an abundance of ammunition. And for a short time the guns popped merrily around that region.

It was rather fascinating to crouch there and watch the curls of smoke shooting up, telling Rob that he was looking upon a real battle on a small scale. Presently, however, when the bullets coming from various quarters below began to whine about his ears, the patrol leader decided that he had better draw in his head, very much after the manner of a tortoise, and make himself scarce, since he seemed to be in the line of fire.

Once, a little later, when he took another cautious observation as the shooting slackened, he was thrilled to see a creeping soldier, clad in a dirty white uniform, not more than thirty yards away from him! Indeed, Rob could watch him carefully raise his head and look downward, as though marking the advance of the foe, so as to calculate on his line of retreat, and the expression on his swarthy face was plainly visible.

"How easy it would be for me to pick that fellow off, if I were a rebel right now," the boy told himself with something like a chuckle, as he slowly advanced his rifle under cover of the sheltering rock and drew a bead on the skulking figure in the Federal service uniform. But of course this was only a little act of boyish bravado, for Rob did not have the least temptation to fire and injure one of these men. He believed that Americans could as yet have no particular interest in this civil warfare that was going on south of the Rio Grande; and that the Mexicans would be all the better for settling their differences among themselves.

Of course, if it went too far, doubtless Uncle Sam, in his character of policeman for the Western Hemisphere, might have to intervene and try to restore peace to the harassed country of the dons.

Seeing which way the Federals were retreating, Rob changed his own course again. Of course he wanted to avoid any collision with the three who had been lying in ambush, and at the same time keep clear, as well as he could, of the advancing rebels until such time as he could let them know that he was a friend, and not an enemy. These fellows were only too ready with their guns to open fire on the slightest provocation, and Rob did not yearn to be made an object lesson.

"As like as not," he was saying to himself as he shifted his position again and again skillfully, "they'd bang away if they saw so much as the crown of my campaign hat, and then apologize in their Mexican way after they'd riddled me with bullets. But an ounce of prevention is a heap better than a pound of cure, and I guess I'll keep out of the way till the right time comes along to speak up."

And having thus made up his mind as to what his course of action would be, Rob began to hold back. He fancied that before long the advance rebels must be coming up, when he could get in touch with them, so as to let them know that the enemy had slunk away after the manner of a beaten cur.

Five, ten minutes passed. There had not been a shot exchanged for all that time, and Rob was really beginning to grow impatient, when he fancied he caught the mutter of voices. Taking another careful peep, he discovered several men, whom he recognized as rebels, for they were armed, alert, and wore no uniforms whatever.

So the scout waved his signal flag above the rock, and at the same time called out in a loud voice a word that he knew stood for "friend."