In order to explain Guadalupe’s presence at the grated window in the top of Billie’s prison-house, it is necessary to recount the happenings at the Hacienda del Rio and vicinity since the hour that Billie plunged from the top of the rock into the midst of Don Rafael’s band.

It was shortly after noon when Billie’s accident happened, and Donald and Pedro were on their way to send for the rurales. As we have seen, Adrian and Don Antonio ran to Billie’s assistance, but were too late to discover his whereabouts. They did, however, find his hat, and, in searching more closely, also discovered the print of many feet on the sand along the bank of the creek.

Upon making this discovery, Adrian led the way up the creek for several hundred yards, and finally arrived at a place where the creek seemed to flow right out from under the side of the mountain.

This solved the mystery. There was undoubtedly a cave under the mountain, which was entered by means of the stream. Adrian was for getting one of the small boats he had seen on the banks of the Concho, and going immediately to Billie’s rescue, but Don Antonio advised that nothing be done until the rurales arrived and there was a sufficient force to arrest Don Rafael and his band.

Adrian finally agreed to the plan, and, after a careful survey of the location, he and Don Antonio returned to the house.

When Donald heard what had happened he was even more insistent than Adrian had been that they should proceed at once to examine the cave. If they found it was in possession of Don Rafael and his band, Donald was in favor of forcing their way in, no matter what the opposition.

“I am sure that would be very unwise,” declared Don Antonio. “Our messenger is already on his way to Presidio del Norte to summon the rurales. They will certainly be here by daylight tomorrow morning. Then we can go in force and will be sure to succeed. If only four of us go, we will probably be overpowered by numbers and your friend may suffer. Let us have patience.”

“Well,” replied Donald slowly, “I’ll agree to wait until morning; but, if the rurales are not here by that time, I shall go after Billie, if I have to go alone.”

“You won’t have to go alone,” said Adrian. “You know that.”

“Indeed you won’t,” chimed in Pedro. “I remember what you did for me.”

The night passed slowly to our boys, and they were up the following morning at sunrise. Coffee was served soon after, and still the rurales had not arrived.

A few minutes later the messenger sent to summon them returned to say that, owing to a report that a quantity of arms were to be run across the river lower down the Rio Grande, most of the rurales had been sent thither, and would not return till morning. This meant they could not possibly reach the Hacienda del Rio before noon.

“That settles it,” declared Donald. “I’m going to find Billie.”

“And I, too,” said Adrian. “I’ll bet the place the rurales have gone is at the same place we lost old Bray.”

“Where was that?” asked Don Antonio.

“At the hacienda of old Pablo Ojeda,” replied Adrian, and he told of their experience.

“I have heard of him often,” said Don Antonio. “He has always been suspected of smuggling across the border—not only cattle, but liquor, ammunition, and all dutiable goods.”

“I should think the rurales would lock him up,” said Pedro.

“They have, several times, but he has always managed to escape punishment. He has some sort of political influence, which has helped him escape.”

“Well, I don’t care what they do with the old chap,” said Donald. “I’m off to find Billie.”

“I shall stay and guide the rurales,” said Don Antonio. “You boys go and do all the scouting you wish; but take my advice and do nothing rash until I come with the rurales.”

Promising him they would be careful, the little party of three set out, and Don Antonio went to his study to do some writing. Guadalupe, who had stood silently by, listening to the conversation, followed the boys to the great gate, and waved them a good-by, after which she returned to her room and tried to busy herself in her daily tasks. But somehow she could not become interested in her work, and, a little later, calling Tanto, she wandered out into the fields, finally straying to the bank of the river.

For a time she sat on the bank, watching the flowing water, and thinking about the three boys, who had so unexpectedly come into her life. She was much interested in them and their adventures, and her thought went out especially to Billie, whose captivity seemed most hard.

“And he is in all this trouble just because he helped Pedro to escape Don Rafael,” she thought to herself, not knowing that the boys had a mission of their own. “I wish I could do something to help him.”

After a while she arose and walked slowly up the river, toward the spot where Billie disappeared.

“I mustn’t be walking in this direction,” she suddenly thought, “I might get into trouble.”

Espying a cow-path, which seemed to lead away from the river, she turned to the left, thinking that she would come out into the open field after a little. Instead, she found herself going deeper into the woods, and after a few minutes again sat down to rest, before retracing her footsteps.

She called Tanto, but he did not seem inclined to lie down. Instead, after the manner of dogs, went off on an exploring expedition of his own.

Guadalupe must have fallen asleep, for she was awakened by Tanto licking her face.

“Go away,” she exclaimed, springing to her feet, and then she noted that it was afternoon.

“I must have slept a couple of hours,” she thought. Then, as she started back by the way she had come: “Come, Tanto, we must be going.”

But Tanto refused to go, and when she turned to call him, he indicated by every means he could that he wanted her to go in the opposite direction.

“What is it?” she asked.

Tanto barked loudly, and again started off in the opposite direction, stopping every few feet and looking back to see if she were following.

“Do you want me to go that way?” she asked, taking a few steps toward him.

The dog barked joyfully and gave every evidence of pleasure.

“Well, go on, then,” she finally said. “You may know the way home better than I.”

Off went Tanto on a gentle trot and Guadalupe followed as best she could.

Tanto led the way up a little hill and down the other side to a ravine of some depth. It didn’t look very inviting, and Guadalupe stopped.

“I’m sure this isn’t the way home,” she exclaimed. “Come on back, Tanto.”

But the dog refused to obey, and continued his antics.

“Well,” thought the girl, “I might as well see what he has found,” and she again followed him until he came to a spot were the path terminated abruptly in front of a steep bank which was covered with vines and underbrush.

Up this bank Tanto scrambled, and, with nose to the ground, emitted several sharp barks.

“What is it?” asked Guadalupe, as she, too, climbed to the top of the bank, noticing as she did so that she could see the river through the trees fully half a mile away.

Again the dog barked and put his nose to the ground, while, with his feet, he began to scratch among the leaves.

Looking down to see what he was trying to get, Guadalupe saw the grating, and, a moment later, she was down upon her knees beside the dog.

The grating was partly covered with leaves, so that at first the girl could not make out what it was. Brushing these aside, the opening was revealed, and a moment later she had her eyes down as close as she could get, and was peering into the darkness.

As her eyes became accustomed to the darkness, she discovered that she was looking into a large room, and gradually she could make out the various pieces of furniture. Then she discovered there was someone on the bed, and having no doubt as to who it was, she called:

“Don Guillermo! Don Guillermo!”

This was the sound which had attracted Billie’s attention.

“Is that you, Don Guillermo?” she asked.

“Yes,” came the whispered reply.

“Are you hurt?” she next asked.

“Not much.”

“Are you a prisoner?”

“Yes; but I’m not going to be long.”

Guadalupe could see that he was getting upon his feet, and partly arose to shift her position, when Tanto sprang back with a deep growl. The next instant she felt herself seized from behind, and, when she would have screamed, a hand was placed firmly over her mouth.