Closer and closer came the clatter of the advancing hoofs. Presently a horseman's head showed above the ridge.

The almost formed command was abruptly checked on the captain's lips, as the newcomer, followed by twenty others, swept over the ridge.

It was Mr. Merrill, and close behind him came Coyote Pete and Bud Wilson, with Jack Merrill riding alongside.

"Yip-yip-yip-y-ee-ee-ee!" yelled the cowboys, as they saw the Mexican troops.

"Wow!" yelled the Mexicans.

"Hooray!" shouted the boys, and, amidst all the rejoicing shouts, there came a sudden cry of recognition from Jack as his eyes fell on Walt Phelps' mount.

"Firewater!" he cried, and the pony shared his greetings and congratulations with the three newly-recovered members of the party.

It was soon told how Coyote Pete and Jack, with Jim Hicks and old Sam Simmons, on their way from the dam, had fallen in with the Merrill party near the mission. It was believed that Black Ramon and his men were ambushed there. Then they had decided to make no attack at once, but close in on the place when the troops had been met with, and in this way make the round-up of the rustlers complete.

Ralph, Walt and the professor rapidly told of their escape, and Jim Hicks emitted a whoop when he heard that the treasure had, in all likelihood, been located. Further relation of all their exciting adventures was put aside by them all till Ramon and his band should have been captured.

After a brief consultation, it was decided to advance in a fan-shaped formation on the old mission, gradually closing in as they neared it. If Ramon and his band were ambushed there, they could make deadly defense from its strong walls, and neither Mr. Merrill nor the Mexican captain were anxious to lose any men if it could be helped.

Accordingly, the line moved cautiously forward till it was within a few hundred yards of the building. Up to that moment the old place had been silent and deserted as a tomb. Suddenly, however, as the attackers advanced, a fusillade was opened from the tower. Lead spattered on the rocks about them, but, fortunately, nobody was hit. Ralph turned rather pale. It was the first time he had ever been shot at.

"Better get behind this ridge," said Mr. Merrill, as the fire grew hotter.

Accordingly, the attacking party dropped low into a gully. The firing instantly stopped.

"If only we could draw enough of their fire to exhaust their ammunition," mused the rancher.

"I have a plan," cried Jack suddenly.

"What is it, my boy?"

"Why can't we elevate hats and caps on rifle-barrels and let them blaze away at those? That would soon empty their ammunition belts."

"A good idea," said Mr. Merrill, while the other ranchers warmly approved. The preparations to carry out Jack's plan were rapidly made. Soon, what was apparently a head, was poked above the ridge. A perfect fusillade of bullets came showering about it.

"Drop it," cried Jack. "Make it look as if the man was killed."

The ruse worked perfectly. Every time a "head" appeared, a tornado of bullets rattled about it, and the riddled condition of the caps and hats thus held up, bore eloquent testimony to the efficacy of the enemy's marksmen.

Finally, however, the fire began to slacken. Instead of a hail of bullets, only two or three greeted the appearance of a head.

The moment they had waited for had arrived. With a cheer, the full force of rurales leaped from the trenches.

"Come on!" shouted Jack, but Mr. Merrill restrained him.

"Remember, we are in a foreign country, my boy. The rurales must do the work or we shall be in serious trouble."

"Oh, bother," cried Jack, "and I wanted to see the attack."

On swept the rurales, a final fire hailing about them, but a volley from their carbines soon silenced the last feeble attempt at defense.

"I guess the rustlers have about given up," exclaimed Jack.

Suddenly, from the old mission gates there swept out a figure on horseback. It was instantly recognized as that of Black Ramon. He was mounted on his magnificent black horse, and waved his hand defiantly at the advancing line. The rurales poured a perfect storm of bullets at him, but the chief of the cattle rustlers seemed to bear a charmed life. Once he reeled in his saddle as if he had been hit, but he instantly recovered himself.

Spurring his superb mount, he sprang forward over the brow of a protecting ridge, and was lost to view. When he next appeared he was silhouetted in striking outline on the summit of another ridge of foothills. For an instant he paused, and they could see him look defiantly back. Then, with a wave of his sombrero, he vanished. It was useless to pursue him. There was not a horse among the ranchers or the Mexicans that could approach the big black.

"There goes a rascal that would look better decorating a telegraph pole with a hemp necktie around his yellow throat, than anywhere else," said one of the Americans, as the desperado vanished.

"And yet," said Mr. Merrill, "I should not have wished to see him shot down in cold blood. If only we had our horses and cattle——"

"We'll have them before long," said Ralph quietly, as, with a loud series of yells, the rurales charged into the mission itself.

"What do you mean?" asked Mr. Merrill. The other Americans, watching from the little knoll the attack on the mission, looked at him questioningly.

"We've found them all," announced Ralph calmly, "in the sunken valley——"

"A remarkable geographical 'freak,' if I may use the expression," broke in the professor, "at some remote period of the earth's life——"

"Yip-yip-y-ee-ee-ee!"

Coyote Pete and Bud Wilson set up loud yells, which were joined in by the other cow-punchers and Americans, as the little Mexican captain could be seen in the distance, waving his sword in token that the cattle rustlers' stronghold had fallen. The whole cavalcade, with a cheer, Swept forward, with Jack Merrill, Ralph Stetson and Walt Phelps in the lead. The professor's horse ran away with him in the wild stampede, but luckily, by dint of fastening his bony fingers in its mane, he managed to hold on.

Without a single life being lost, or any wounds received on either side, the band that had so long harassed the border had fallen into the hands of the authorities. Eventually every member of it but Black Ramon was rounded up, including the renegade cow-puncher.

All were placed under escort of the troops, and taken to Mexico City. They are now serving long sentences in Mexican penal institutions. The Border Boys later received the thanks of President Diaz for the part they had played in bringing the outlaws to book. After seeing the prisoners disposed of, of course the Americans had to be shown how the boys and the professor had effected their escape from the church. With torches and lamps they crowded into the narrow pit, and the hole which had gaped open when the ring was pulled loose soon appeared. Of the noxious gases, however, no trace remained. The air was pure and healthful. The professor ascertained later that the old missionaries who had buried the treasure there, had placed pungent chemicals under the trapdoors, so that, in case of marauding Indians attacking the treasure, it would be safe. The skull and bone, it seemed reasonable to suppose, had been placed in the passage wall as a warning to other visitors. The mysterious noise that had alarmed Ralph remained a mystery for a long time, till one of the prisoners admitted that he had caused it under Ramon's orders, the object being to scare the boys.

The lights of the torches and lamps carried by the party, shone redly into the black hole, and the three Border Boys peered eagerly over. Jack and Ralph, by a common impulse, leaped downward together. Their feet struck the lid of an old wooden chest with a splitting, rending sound, as the rotten wood gave. The next instant a cheer went up. Jim Hicks' treasure-trove had been found. The flickering lights gleamed on the dull glint of gold coins and ornaments of priceless value.

"Wow!" yelled Jim Hicks; "I'm rich. But so will you boys be, too. I'll take care of that, and you, likewise, Coyote Pete."

In vain the boys protested; Jim Hicks insisted, and long afterward, when the Mexican government's claim had been settled and the treasure appraised, each boy received a crisp check for two thousand dollars. Coyote Pete was also a recipient of the miner's good will.

Among the prisoners taken, was a queer-looking old man, with a long, white beard, and the quick, shifty, dark eyes of an ape. Jack Merrill and Pete gave an exclamation of surprise as their eyes fell on him. It was the old hermit of the caÑon! He recognized them, and gave them a baleful scowl.

"It wasn't his fault that Ramon didn't have us where we've got him," commented Pete.

After remaining camped at the mission for a day, while final arrangements for the taking of testimony at the cattle rustlers' trials, and the matter of the boys' depositions was attended to, the American party bade farewell to the Mexican captain and his troops and set out for the home-side of the border.

Carefully guarded by several cowboys was a pack horse, carrying the treasure chest. Its contents had been roughly valued at $75,000.

"Well, Ralph," said Jack, with a laugh, as the boys rode along at an easy lope together, "what do you think of the West now?"

"It's great, Jack," responded Ralph, who had been thinking over the adventures of the last few days.

"But if things had turned out differently," put in Walt.

"No use thinking of that," decided Jack. "All we've got to think about is, that we have had the luck to be the means of cleaning out that bunch of rustlers, and ridding the border of them forever."

"Forever's a long time," commented Mr. Merrill, who had spurred up alongside the boys. "However, I think you boys have had quite enough adventures for a time."

"I'd like to start out again to-morrow," exclaimed Jack.

"So would I," echoed Ralph.

"Well, you may have a chance before long," said Mr. Merrill enigmatically. He would add nothing further, however.

At Maguez a great reception had been prepared for the returning ranchers. The celebration was held some days later. The boys, their faces suffused with blushes, had to make speeches and describe in part their adventures.

"Three cheers for the Border Boys," yelled the crowd, as Ralph limped through some sort of an oration. Jack had done much better, while Walt Phelps was overtaken with stage fright and couldn't speak at all.

"Well, good-bye to the strenuous life for a while," said Jack, as they rode home after the celebration. Behind them were the yells and whoops of the enthusiastic citizens who were still keeping it up.

"Well, we've been through many dangers and perils," rejoined Ralph, "but somehow, it's pleasant to look back on them. I hope we will have some more adventures before long."

"Not likely to," commented Walt Phelps.

"Why not?" asked Jack. "Black Ramon is still at large, remember, and somehow, I've got a feeling that as long as he is at liberty he'll make trouble."

"Well, the Border Boys will take care of him every time," shouted Ralph, giving a regular cowboy yell:

"Yip-yip-y-ee-ee!"

It was echoed by the other Border Boys, as they spurred forward for the home ranch, under the clear stars. On and on they rode, their little ponies' feet making the lively kind of music each of them loved best to hear.

All at once they rode over a slight rise—the first "land-wave" to mark that they were approaching the foothills. With yells, the Border Boys dashed down the other side of it and disappeared from the starlit desert trail—and from this story.

But we shall meet the Border Boys again in further adventures and perils, more exciting than any through which they had yet passed. Ralph Stetson's introduction to frontier life—thrilling as it had been—was but one series of incidents in the lives of the dwellers along "the line."

How the Border Boys were tried in future stirring scenes and exciting adventures, those who choose to follow their career may find related in another volume of this series, which will be called: The Border Boys Across the Frontier.

THE END.